For example, in substrate-based blockchains if you panic in runtime code, the chain is effectively bricked, so they use hundreds of clippy lints to try to prevent this from happening, but you can only do so much statically without language level support. There are crates like no_panic however they basically can't be used anywhere there is dynamic memory allocation because that can panic.

Same thing happens in real time trading systems, distributed systems, databases, etc., you have to design some super critical hot path that can never fail, and you want a static guarantee that that is the fact.