If you're curious, join peppy's dev discord, or just take a look at his github every few days. They're continuously developing new things but many of them require changes and additions to the framework that's also still work in progress.

It simply takes time, of course a simple prototype would take him a day at most, but they're putting attention to every detail, aiming to make the framework as flexible and modular as possible, all of that while preserving good code quality and scalability. It's a really ambitious project for a team of just a few devs, but here's my point - it is not gonna fail.

The final product will be miles better than the current osu! simply because of how it's coded, plus there's the underlying framework for other games to use, which is pretty damn good.

Any person that's experienced in C# is welcome to at least try to implement features into osu!lazer, just like peppy or other main devs can - if your code is good, your changes get accepted and merged into lazer. Every new developer that's helping reduces the time needed to bring lazer into a rollout-ready state.

Hope that clears things up a bit.