While there were portable devices that could connect to a TV before Switch, such as Nomad and PSP, the concept of a "hybrid" handheld/home console didn't really catch on and become a breakout phenomenon until Nintendo's 2017 hit.

Do you think this could have been achieved in a previous generation? Or were the technology and circumstances just not in place yet til last gen?

Nintendo's handhelds have always been successful. (Except virtual boy) So... With that in mind, ceding the fixed home console market to Sony and Microsoft and rolling all their development teams to focus on a single platform made sense. So absolutely they could have generated that success earlier.

Competent mobile chips did exist before the Switch existed.

While it was possible for Nintendo to make a 'Switch' during the Wii era, it would have been less successful. The DS and Wii were just too different to mix up without cancelling out what made them unique. The 3DS and Wii U era was more possible, but it required a non-existent 3DS, which gave Vita no real competition in the hand-held only realm, perhaps.

Anything earlier than Wii would require them to have much weaker systems. Imagine a much weaker N64, or SNES. NES wouldn't even have the technology.

The 9th generation was really when the strategy had the best chance in succeeding.

They picked the best possible time, but some earlier years were possible.
PSP launched in Japan in late 2004 and was closer to a PS2 in specs than most would've expected. Nintendo might've been able to release a Switch around 2006 that was similar specs to Wii in docked mode and around a GameCube or slightly weaker in handheld (to conserve battery).
2012-2013 might've worked out as well. Just don't make the 3DS or Wii U and release a hybrid platform around PS3/360 specs (in docked at least).
I don't think mobile batteries and chipsets were really there before 2004 for a hybrid to be worth it. A hybrid shouldn't just be handheld-like games on a TV, but a home console experience too.
PSP could've been a hybrid, and it IRL it nearly was. It never had a dock and component cables were sold separately. But still, if you bought them, you could hook it up to a TV.
If PSP was a hybrid in real-life with similar specs (maybe boosting up slightly past PS2 in docked mode) it could've decreased Sony's reliance on PS2 while PS3 struggled out of the gate. There's no way I could see the PS3 itself as hybrid. A successor to PS2 with barely better specs would've probably been an even crazier decision than Sony already went with in the many expensive PS3 decisions they made.

Had Switch released in 2012? It would’ve inherited all the same problems as Wii U, just with a more novel gimmick. Software output still would’ve been scarce because the problem wasn’t entirely the dividing of labor between two systems, as much as it was Nintendo being caught off-guard by the demands in producing HD software. (IIRC this is what they were stating constantly during pre-release and early years of Wii U, as an explanation for the lackluster lineup of first-party software.) Marketing would’ve been met with the same issues. Etc.

Had Switch released in place of Wii? It probably would’ve been no different than what we ended up seeing. The novelty was already seen in the motion controls, and was enough to create a widespread shortage of systems for years. Had Switch released in place of GameCube? That would’ve been revolutionary for the time, but the success of the system would’ve entirely relied on how well it was priced. Nintendo knows how to sell handhelds, but prior to Switch, it was heavily dependent on economics. In place of N64? I have literally no idea how consumers would comprehend this lol but noting how detrimental the price of N64 was to sales, my guess is that it would’ve been almost entirely dependent on economics. (If OoT and Mario 64 wasn’t enough for N64 to go much further than even a third of PS1 sales, then hybrid functionality would’ve needed to be met with generous pricing.) SNES and NES is a similar story: likely would’ve been left with a Game Gear situation, where the battery would drain out within 30min, selling for an unreasonable price.

Perhaps.

But the craziest thing about the Switch is how Nintendo left the dedicated home console market and managed to do so without anyone noticing. Talk about a genius plan.

No, the technology wasn't there yet. You have to remember that Switch was deemed underpowered at its launch and at the same time its battery life barely crossed the line for passable when it came to home console games. The storage capacity for game cards was insufficient to make a Switch-like device and an optical medium would have been shit for portable hardware.

Additionally, it wasn't so long ago that graphics have reached a point where hardly anyone cares about them anymore. Originally, Nintendo's handhelds in terms of processing power were two generations behind home consoles (SNES vs. GB, launched in 1990 and 1989). The gap was closed to roughly one generation with the Wii and DS and it took ~15 years for that to happen. Or in other words, a hypothetical hybrid in 2006 would have featured graphics between the levels of N64 and GC which wouldn't have been good enough.

2017 (or late 2016 as originally intended by Nintendo) was really the first opportunity to make it work because processing power, battery life and storage medium weren't advanced enough before that time. The key to Switch's success wasn't that it was a handheld that can connect to a TV, it was that it is a home console that you can take on the go.

I totally agree with the way you said that.  And would the technology/cost available prior, be able to accomplish that?  I say probably not, because the Switch itself barely got a pass. 

Technically, kinda yes.

2010 saw release of two SoCs that had around 70-75 GFLOPS (PowerVR SGX554MP4 and ARM Mali-T604MP4 ), which would, technically, kinda let them have "Switch like" ports of PS360 games. (in comparison, PSVita has 28.4GFLOPS on SGX543MP4+)

But that proto-Switch would cost arm and a leg, since first devices with those chips actually released some year and a half later, one in iPad 4 and other in Samsung Galaxy Note/Tab 2 10.1 (2012).

So technically, yeah, practically no.

Not really in that same kind of form factor. Even Switch 1, Nintendo's hardware designers in the Switch 2 Q&A mentioned they weren't happy with the Switch 1's (Tegra X1) chipset's performance.

Tegra K1 and Tegra X1 were still early days of Nvidia moving into that mobile space, now you see the Tegra T239 in the Switch 2 is able to run PS5 tier game thus far much better than the Switch 1 could handle PS4 games. Part of that is probably because Nvidia has simply gotten better with their chip tech over the years.

That said, I do always wonder if maybe Nintendo should have tried to pivot the GameCube into a semi-portable console that could maybe run off a laptop style battery. Obviously it wouldn't have been a handheld form factor really, but it probably would have been better than what they had going (could have included a Game Boy slot too).