Modding and retro games question

I have a friend with a gamecube who intends to sell it for a modded wii because that would allow him to do more. He also plans to mod it and get these gamecube games digitally. Would he be better off with a Wii U nowadays? What he's looking for is a machine to play gamecube games but with more features. That's why I considered the Wii U because nowadays it seems like a modded Wii U can play everything Nintendo has ever put out besides 3DS and Switch.