I love that. My wife and I are hopefully having kids soon and that's one thing I really want to encourage. Not to say that modern games aren't any good, but there's an increasing lack of respect for the player's time and wallet. The goal is shifting to maximizing value because they're getting more expensive to produce, but increasing the game price itself is a cardinal sin. Not to mention that live service games just out-earn non-service ones.
I hope it works out. I can see it working in the reverse: I play n64/ps1/ps2/gamecube games with my kid, they go to school and their friends are playing fortnight or valorant, and then you become the bad guy for trying to be an obstacle in that.
Let your kid go over to their friend's house to play Fortnite or Valorant. And let your kid's friend come over to yours to play Mario Kart.
I think as adults we get locked into a few things. I remember as a kid I would play anything I had access to and liked. Now it's more of one or two games at a time.
One thing that's absolutely shocking is how "hard" it is to actually play games these days. Sit down with anything modern and between software updates, EULAs, load times, network congestion, etc. it can easily be 15-20 minutes before you actually do something; especially if you're an infrequent player.
Pop in a game on N64/Gamecube and you're controlling the character within 10 seconds every time.
The modern upgrades for those generations really make them great - the 8BitDo kit to make an N64 controller wireless, N64 Summercarts, replacing the optical drive in Gamecubes with a memory card reader...