Games draw every single object on the screen every frame. They don't lag, quite the opposite in fact!
There is also the issue that GPU's are oddly terrible at generating 2D elements of which a desktop has thousands of them. There are things like Glyph caching but they can only go so far.
Having the CPU doing the majority of the work with a few rasterization tasks to the GPU makes sense.
I never knew this and honestly I’m a bit baffled - 2D seems simpler on its face, is it just that GPUs have been made with gaming in mind (typically) and most “hardcore gamers” are playing 3D games?
Not sure where that went in the end.
Games 20 years ago had sole access to machines that were much less powerful than even partial access to today's machines.
And eg Nintendo Switch games (or games on the Steam deck, or just mobile phone games) still deal with power limitations; people are very aware when their games burn through their batteries.
