I think the way controller is now is fairly great and don't mind if that layout is fairly set in stone.

If I'd want anything is to just include back buttons as a standard. Those expensive "pro" controllers and 3rd party controllers have them. Last gen the PS4 controller even had an add-on for back buttons.

Using the Wiimote when it came out just wasn't for me, and if every gen kept coming with different gaming controllers as the default then I probably would've lost interest in video games.

I think so. I'm generally in the party that somewhat prefers simplicity in interface, but complexity in what it can execute. A very good example is what a computer mouse, the DS's resistive touch screen, the Wii's IR pointer and gyro controls, and the iPhone's capacitive touch screen achieved in past times for their various applications. The Switch's multi-use joy-cons don't get enough credit for the design philosophy it achieved either: a simple single controller, dual-handed controls, a traditional controller, and a handheld.

I also still likes the simple NES controller design: A, B, and D-pad. It was an elegant solution to the complexity barrier that had sprung up during that generation. Maybe it's nostalgia. It's still a good design for certain games even today as was shown on Wii, and even the Switch today.

But the real question, are we done? I don't think so. It's not necessarily going to be about bells and whistles but how simple and intuitive the interface can be made while expanding its capabilities. How does that look? That's the multi-billion dollar question. But, some of the examples above are a fairly good indication that these are difficult to predict unless we're heavily considering software design.

I hope so, there is certainly room to grow.

A comfortable split controller with dual analogues, gyro, and an IR pointer would be godlike, think the Wiimote meets the Switch 2 Pro controller.

Yeah this could work, if it has a pointer on the right hand a la Wiimote.

These are controllers for Steam Frame VR, I've seen 3rd party add-ons that you connect them to that makes them like standard controller, so that reminded me of some future ideal controller that can be connected and split as desired.

VR controllers are generally leagues ahead in precision compared to Wiimote, so you have great pointer alike abilities in both hands (I don't have access to these, but even old Quest 2 controllers are really good)

I personally think modern controllers totally suck.  It's mostly this way, because that's what modern "hard-core" grognards like.  And when I say "modern controller", I mean anything that is some variation or improvement to the PS2 controller.  This controller is actually too clunky and complex to further gaming.

For most 2D games an arcade stick is ideal, and I really think 4 buttons should be the max.  For 3D games, there need to be more advances in the Wii remote & nunchaku design.  That is the right track, but there is a lot of room for improvement. 

Also, sometimes a touch screen or mouse is the right controller.  And back in the day we had light guns and trackballs and all sorts of other controls.  I would like to see more experimentation in the types of controls that are used in various games.  As it is, most games are just designed for the PS2-style configuration, which I would call a one-size-fits-none design.  It's not suited for any type of game in particular, but it's more about a controller that can somehow play every game, even if it controls poorly.

They should be standard. I hear the PSVR2 controllers are more favourable with DS5 haptics and triggers.