I see your point, but it all depends on whether the choice of a particular organizational infrastructure architecture is a priority for you or not.
If infrastructure is a priority, (e.g., "we don't really want to hire anyone just to setup/monitor/secure that Linux box with all those REST API server/database processes, thus we prefer serverless), serverless is important and Rust performance is its strength.
If infrastructure is not a priority, (e.g., "I was gonna roll out my own VPS anyway, I love this stuff"), serverless is all about its faults and Rust is irrelevant (it is logical to choose an easier PL, e.g., the excellent Golang).
If infrastructure is a priority, (e.g., "we don't really want to hire anyone just to setup/monitor/secure that Linux box with all those REST API server/database processes, thus we prefer serverless), serverless is important and Rust performance is its strength.
If infrastructure is not a priority, (e.g., "I was gonna roll out my own VPS anyway, I love this stuff"), serverless is all about its faults and Rust is irrelevant (it is logical to choose an easier PL, e.g., the excellent Golang).