Being able to scale to any specific amount of usage is never a reason to use microservices. Plenty of planet-scale services and apps are powered by monoliths. And you never run into any kind of ridiculous overengineering when you refactor things into services for scaling reasons and that's not a microservices architecture in the first place.
The problem has always been about people deciding that different parts of the app that differ mostly in terms of business logic somehow need to be independently deployable. It's like deciding that instead of having a single database cluster and having multiple databases and tables, you need a separate, independently scalable cluster for each database table, because of some bogus reasons like some tables are queries more than others and different teams work on different tables and we can't let people join tables because it breaks boundaries or something.
The problem has always been about people deciding that different parts of the app that differ mostly in terms of business logic somehow need to be independently deployable. It's like deciding that instead of having a single database cluster and having multiple databases and tables, you need a separate, independently scalable cluster for each database table, because of some bogus reasons like some tables are queries more than others and different teams work on different tables and we can't let people join tables because it breaks boundaries or something.