Sandboxing is a mitigation but a very limited one. The library itself can contain a malicious payload -- rust code most often ends up as native code executed on the host.

I think we may need to enter a world where there are fewer, heavily audited, libraries and dependency depth is limited. Allowing unvetted dependencies to be installed by default is not a good way forward. App stores have a similar problem and I think a lot of lessons have been learned there that can be applied.