Not sure I think that's a big argument for microservices/atomic functions but rather just for decoupling things in general.

For me, the appeal of microservices is the organizational challenges it solves (allowing teams to move and deploy at their own pace).

My current codebase is a monolith because we're a tiny team, but the different parts are not tightly coupled more than they need to be and it doesn't feel slow to change things.