> Microsoft adopted the most popular one
That's still consolidation, and it also needs time.
Even in Rust crates like hashbrown or parkinglot have been basically subsumed in the standard library.
Agree, after I thought for more examples. Thanks, don't know why others downvote.
Besides consolidation point, I still think that "barrier to entry" point is still valid -- if it's more effort to even publish a library, its author is probably more committed already.
It's even more pronounced with the main Java competitor: .Net. They look at what approach won in Java ecosystem and go all in. For example there were multiple ORM tools competing, where Microsoft adopted the most popular one. So it's even easier choice there, well supported and maintained.