Using new controllers with retro consoles might sound sacrilegious, but I'd argue modern gamepads can classic setups. Not everyone cares about using authentic accessories, and while I have a massive collection of original gamepads, even I like to kick back with something modern and comfortable that cuts the cord from time to time.
I've been showing people how to use new controllers with retro consoles for decades, and it's now remarkably easy. It feels like only yesterday that I had to conjure up convoluted combinations of adapters or mod systems to grant them modern gamepad abilities, but now, it's as simple as grabbing the right adapter or dongle.