Power consumption, power consumption, power consumption. Your hardware might be as capable as the PS5's but you try running a PS5 on 50 times less electricity.

The API makes little difference, everything is close to metal in one way or another these days. Switch 2 games will find a fairly similar backend, but on a worse node and a GPU with a lower transistor count.

The real question is whether the undocked version will consume more power to compensate for these and surpass the iPhone 15 Pro's in-game capabilities.

The OG Switch, after all, probably runs games a little better than the iPhone X, but Apple has made huge strides in their hardware since.

PS5 is like ~200 watts.
While a docked Switch can go ~30watts or so.

So more like a factor of 6-7x than 50 :P

It's a PS4 port, not PS5.

Edit: also 200ms input lag lol

I don't think the Switch 2 will be anywhere near PS5-level, but the iPhone Pro comparison isn't a good one.

For many reasons: 

1. Switch 2 will have active cooling. This will allow it to run at double to triple the TDP in docked mode and somewhat more as a handheld. The performance difference between 3-5W and 12W-15W is pretty significant, especially when the iPhone is likely thermal throttling at that 3-5W, all else being equal. 

2. Much of the iPhone's price is in its display, camera and build quality, and also there is the Apple tax for being stuck in their ecosystem. Phone prices are also an example of price-discrimination, with the base price being high and then there being heavy discounting based on buyers willingness to pay and carrier subsidies. 

3. The Switch 2 is still about a year out from release. 

4. Developers have more experience and tools developing for Nvidia GPU's than they do Apple Silicon. 

5. Standards for mobile games, for better or worse, are lower than for dedicated gaming platforms, so developers are more likely to take short-cuts. 

But yeah, given everything we know about the Switch 2 it won't be PS5 level. It'll be in the same tier as PS4 Pro, Xbox One X, and Series S in docked mode, and roughly PS4/Steam Deck level in handheld mode.

On the other-hand, iPhones like all smartphones tend to thermal throttle because they're passively cooled.

So even though one would expect about a 20% improvement in performance for 3nm vs. 5nm on the same chipset, and the iPhone's CPU is better, the active cooling for the Switch 2 probably could make up for it in terms of frame-time stability and general performance. Plus as you noted, it could probably pull a few more watts (3W for iPhone, maybe 5W for the chipset with Switch 2, more if it is bigger and houses a larger battery.)

https://www.notebookcheck.net/Severe-Apple-iPhone-15-Pro-Max-thermal-throttling-reported-as-A17-Pro-appears-to-push-surface-temperatures-to-48-C-during-gaming.753143.0.html

Well said, I agree.  I just know some are expecting the switch 2 to ps5 like fidelity, which was the case with apple's new chips.  Hence why I brought up some reviews.  Mobile has limitations.  

Switch 2 will will ps4 with dlss in docked mode.

Yep.  DLSS might push ps4 pro, maybe.  I have a 4070 and 13700, just my opinion but DLSS is nice but nowhere as great as people make it out be.  RT is a fps killer.  Looks great but RT is going to be a challenge for the switch.  My 4070 doesn't do great with RT, I lose 30% fps quickly.  

Any thoughts on the analyst's prediction of a $400 price tag and the switch 2 being an iteration and not revolution?

I don't see how the analyst would know anything more than anyone else, but $400 has been my guess for a while.