> the biggest drawback of async is the fragmentation of the ecosystem
95% of the ecosystem uses tokio nowadays. async-std has been dead for a long while. There are other runtimes for specialist purposes, but pretty much all async libraries will work with tokio, and you should just use tokio. It's fine. It's well maintained. It's not going anywhere. It's hit a stable 1.0. There is basically no reason to not use it.
> So, if you think that you didn't have enough work solving the problems of your users, you now also need to update your toolchains, Dockerfiles, dependencies and more, every 6 weeks.
This is complete rubbish. Rust's edition system means that Rust code written back in 2015 will (largely, bar some minor soundness issues that have been found since then) still compile. You're under no compulsion to update anything, and cargo's lockfiles ensure that your builds don't suddenly break. If you want to upgrade, do so! But it's exceedingly rare that code ever needs to change when doing so. It's about a painless an upgrade experience as it's possible to have in this industry.
> Rust is betting everything on a powerful language backed by advanced theory, but it forgot that developers need more than a language to build solutions to businesses' problems.
No, it didn't. Rust's standard library is not designed to give you everything you need to build a large program. Instead, it's designed to specify the interfaces that other libraries in the ecosystem require to talk to one-another, and it's been remarkably successful at that. Take a scroll through [the docs](https://doc.rust-lang.org/std/) and you'll see that: it's almost all traits, fundamental types, and other shared abstractions that are used by the rest of the ecosystem. Any non-trivial program is supposed to end up with third-party dependencies: the critical thing is that those dependencies can talk to one-another painlessly, and that promise is largely delivered upon: everybody uses the same interface for `Future`, `Iterator`, `From/`Into`, `Allocator`, `Clone`, `Eq`/`Cmp`/`Hash`/`Ord`, `Error`, `Debug`/`Display`/`FromStr`/`ToString`, `Read`/`Write`, `Sync`/`Send`. That's the sign of a remarkably successful and well-engineered set of abstractions.