It has an LLVM backend so adding support for other architectures is not difficult.

JB already ported the compiler to Nintendo Switch several years ago.

https://old.reddit.com/r/NintendoSwitch/comments/cixsoy/jona...

well, given that any random person can't just adopt the language today, the platform support available today doesn't really matter, does it?

Jon is writing it for his needs, and this thread is full of people saying "it doesn't meet my needs!" So what? it's not for you!

Blow is designing and implementing a language for making video games, and in particular, for making Thekla’s video games (Jon’s game company). Blow does not make mobile games, nor does he make small, retro-style games that would typically be run on a Pi. His concerns are modern Windows gaming PC’s and the big three consoles. While Jai is Turing-complete and is ‘general-purpose’, the implementation serves Blow’s needs first and fioremost, so the chosen targets make sense in light of that.

Given that he and his team are developing a language and a game in that language at the same time it makes sense to focus on the primary platforms they work on, and expect their game to currently run.

Their primary platform is Windows, and the game in its current very early state is also running on Windows.

What's the value in porting it to Raspberry Pi or Android?

From the streams it looks like a Linux port is usually mostly up to date, and MacOS understandably lags behind. But neither of these platforms have any high priority for now.