It's only useful if you make unsafe sections and if you make unsafe sections, its safety guarantees are gone.
It's not a serious language, it's a social movement looking to force itself into being seen as useful. That is why instead of creating lots of new projects with it, it is mostly used to rewrite (usually through automated processes) existing code that the Rust social movement then can claim ownership over and credit for making. They want to be able to say things like>Where would be world be without the Rust social movement? 99.99% of communications is only possible due to Rust code created by the Rust social movement.
Their latest target is the Linux kernel, which they desperately want under the control of their social movement. This has already been seen in many other FOSS projects where the social movement has taken over the work of others and claimed it as their own, pushing out the original creators, and overseeing the decay of the project due to their incompetence.
While the members of the Rust social movement are doing it for socio-ideological reasons, their funders in the multinational corporations are doing it because they want to take over FOSS. Setting up these puppets they can control is the best way to do it without being seen directly as taking over.