I've been retro gaming on my Google Pixel Fold with a GameSir X2s Type-C controller, and I have to give it a shoutout. It's got Switch-like ergonomics in a... PSOne (?) reverse-GBA(?) colorway, with the C-connector on the left, which is perfect for foldables. DS emulation has never been better! I carry one around in my backpack at all times. And today I saw it's a "Prime Big Deal" on Amazon for 28 bucks, which is almost half-off, so I bought a second one this morning for my bedroom nightstand.
Some folks in the Amazon reviews have said that they've had trouble using it with a phone case, but I've found the length of the C-connector to be quite generous (granted, sometimes I have to push it tighly closed for it to register), so YMMV. $28!
https://a.co/d/clcweUs