I'm intrigued by 8th - in a good way - and happy you've introduced me to it - but I do wonder what kind of uptake something like this will get.

By that time Rust will also mature enough and webasm will land so Rust will probably be a better candidate (since it's OSS and developed by a browser company that needs to run on as many platforms as possible they have much better incentives to maintain ports than Apple).

Also in that time C++ will probably get modules working on clang and many c++17 features.

And you might see Xamarin merge into CoreCLR and rolled up into VS integration.

A lot of things are possible - but what's available right now is C++ on every platform and not much else.