She was asked which was the most challenging platform to build on and she said it was by far Stadia due to having to accommodate all of the different screen sizes from TVs to phones to tablets. It was tough getting the UI usable across all.

... which is kind of weird because with Stadia, as far as I know, the only new resolutions devs will now need to take in account is smartphone resolution.

Every other resolution should already been taken in account (TV and PC) since tablets are now usually similar to PC resolution.

I guess video games devs aren't used to web responsive design and to be honest, I'm glad they'll have to take that in account: most of UI issues on PC are related to it (you know, when the game doesn't support some a specific resolution, or when you hove something an UI item with your mouse and it doesn't seem to be taken in account).

This is actually good for gamers.