Out of the box, Pocket is compatible with the 2,780+ Game Boy, Game Boy Color & Game Boy Advance game cartridge library. Pocket works with cartridge adapters for other handheld systems, too. Like Game Gear. Neo Geo Pocket Color. Atari Lynx & more. Completely engineered in two FPGAs.*
More clear cut value proposition though, you know what you are getting. With Playdate you are taking a bigger risk on the games, and getting much less power.
scalpers generally don't care about how clear cut the value proposition is. For example they bought up all the game & watch super mario handhelds right away, which has literally only 2 games on it and not enough onboard storage for much more than that. Scalpers still bought them all up. Luckily Nintendo kept shipping them out so you can get them pretty much anywhere still, unlike their amiibos.
More clear cut value proposition though, you know what you are getting. With Playdate you are taking a bigger risk on the games, and getting much less power.