Existing android socs up to and including ps/dreamcast/wii works normally
The steam deck can also handle switch (only SD socs partly on android) and wiiu (not yet available for android) and also partly with ps3

For xbox360 and later or ps4 you can currently handle gamepass / playstation + (streaming from console or cloud)

And for anything that requires more power or compatibility, you can use moonlight (or similar) to stream from your computer if it’s powerful enough.

And for those of you wondering, yes I personally have the games I run on it (yes that won’t be the case for everyone, yeah) but what makes a similar device so attractive is the buildup.
You don’t have to keep getting gc, wii, wiiu, ps2… out of the attic, tied to consoles that are sometimes awful by today’s standards
Just cute on one thing easy to take with you

Because of this particular hardware, I think aya neo releases nice stuff, albeit usually quite expensive, but not really imo
Especially the smaller screen (or OLED here) compared to Ayn’s direct competitor is a downside.