I would hesitate to call it total dominance. There's a lot of good competition arising in this space. If you haven't already, check out pixi for example. And yeah, pyrefly is fantastic.

Competition is good in this case.

Why is that a good thing?

I don't think that the whole ecosystem should be dominated by a single VC backed startup.

I want my tools to be interchangeable and to play well with other choices.

Having multiple big players helps with that.

Maybe I'm wrong on this, but I rather have 1 tool everyone else is using. Cargo in Rust ecosystem works really well, everyone loves it.

Imagine if Cargo was not first-party, but a third-party tool belonging to a vc startup with zero revenue.

Then that startup makes rustup, rustfmt and rust-analyzer. Great, but I would be more comfortable with the ecosystem if at least the rust-analyzer and rustfmt parts had competitive alternatives.