iPad can run the game, it’s for sure. Now we can easily use bluetooth keyboards and mouses or xbox controllers to play the games without touch interface on the iPads.
But it’s still a different OS and it needs big investment and profits from it. There are not so many owners of last iPad Pro around the world, that the development to be successful and, as far as I know, the Sims 5 is in pre-alpha now. Also, not every devs are ready to give 30 or even 15% of sales proceeds with Apple
So, we’ll have to wait until Apple’s macOS on iPad’s release, which is more realistic scenario than EA to port the game on iPadOS. Or, maybe, we’ll see the Sims 5 on it soon!