Wanted to give my cousin (11) a handheld since he’s never had a game console.
He saw my stepsister’s PSP and was interested in it but she wanted to keep it.
Would like the system to be as simple as possible since he’s not very tech savvy but also be able to play some PSP games since that’s what piqued his interest.
Budget under $100 just in case he doesn’t like retro games
You can probably find a Vita 2000 for around $100. It’s super easy to mod and swap in an SD, and it can play PSP ROMs using native Adrenaline software.
There are newer and more powerful options, but for something straightforward to use, a Vita is still a good option.
Anbernic handhelds are pretty good for low price, not sure if the cheaper ones can emulate PSP though
Retroid Pocket S2 is very good on that price tier
Back in my day we all had cup and balls and it was hours of battery-free entertainment.
Steam Deck. Tell his parents how to use the Family mode recently added to Steam accounts (there should be instructions for setting up an account for the parent and then creating the child account, allowing complete authority over various aspects like requiring the parents to manually approve all purchases), and that they can restrict the Desktop Mode behind a PIN so he can’t screw it up. It’s over your budget but it plays non-retro games and is the cheapest reputable handheld by far AND the most reputable handheld period.
Sadly, the Switch 2 is dangerously ephemeral: They’ve literally swapped the game itself for the license to play a game, your cartridge only contains the license and the data leaves when the console is no longer supported.
I wouldn’t bother with anything else, if you spend only $100 you aren’t going to get anything but a cheap plastic waste of money, and most other gamerdecks run Windows 11 so that’s not a reasonable option.
EDIT: If you buy used, this might not apply, as actionjbone stated.