Gaming setup for kids?

Our boys (5 and 8) are really getting into gaming. They currently have a first generation Nintendo Switch and an ipad. They primarily play Minecraft, but are starting to get into some more advanced games like MLB: The Show and Among Us.

The problem is that they’re beginning to prefer the Switch, which is on its last legs (I was playing this thing when my wife was in labor with our first born and the screen is destroyed / battery is showing wear.)

So the question is: where do we go from here? Do we get something like a Switch Lite and try to repair the OG Switch? Do we upgrade to something like a PS5? Primary goal is to give them something they can play separate AND together and ideally good with cross-platform co-op.

PC is out of the question right now because of the hardware costs.