If you want CRT support for your Pi4 or Pi400, try RGB-Pi 's "OS/4". it's snappy and less bloated that RetroPie. Here's how to use it with Pi2SCART : r/RetroPie
Emulation - Retro gaming sur Raspberry Pi [Topic unique] - Page : 238 - Consoles - Jeux Video - FORUM HardWare.fr
Pi2Scart Raspberry CRT TV GPIO Converter Board PC2 Pi 2 SCART PCB Arcadeforge | eBay