I feel like the Miyoo Mini is a bit overhyped at this point. The original had a nice size and feel to it, solid custom firmware with GarlicOS, and lots of fan made physical add-ons like stickers and 3D printed cases to personalize your device but you can't really buy it anymore and while there is the Plus variant that added WiFi that sounds a bit overkill for what OP wants.
Are you talking about something you hook up to the TV? A raspberry pi is a great option but you need to provide your own games. It's just going to be the most flexible for playing whatever game you want. There are a couple distros for it that are easy to use once setup (retropi, recalbox). An RPi 3 or newer will do anything lighter than N64.
There's loads of options. All depending on your budget
Abernic RG351V is currently a nice low price, for a 351 device. It can play up to psx flawlessly and handheld it could play up to DS, but it is not recommended for obvious reasons.
Other abernic devices might also work. I have the RG351MP myself, and am very happy with the build quality.
Take a look at this video for some recommendations released last year from first had experience from a guy who plays on a lot of these devices. His channel should be your go-to stop for any retro handheld devices.
YouTuber RetroGamesCorp is pretty popular in the community and he's got a video with his favorite devices of 2023 that has a section for budget handhelds. He recommends the R36S. It will get you up to PSX smoothly.
In may of last year people were talking about a device called the DataFrog SF2000 which was incredibly cheap at $25. It has screen tearing and slow down for GBA games. I haven't heard anything about it in a while so I don't know if a custom firmware was ever released to fix some of these issues.
One other thing you might want to look into is picking up something like a DS Lite and flashcart because at that point you can play all NES, GBA, and DS games.
I would 100% steer clear of any of those 100 in 1 devices. Most of the time they are limited to NES games. Once you are tired of the few games they can play it's basically E-waste. At least with these other devices you can add games.