We avoid monoliths, and microservices can handle more requests per second if you develop them in the right way, but using microservices doesn't mean you have a scalable application effortlessly. It makes any part of an application flexible for scaling, and you have to write loosely coupled microservices that can run in many instances.
Scalable architecture
Basic ideas
To make an application scalable, you can choose one of two approaches.
In the first case, you can start more copies of the whole application. You may think it's impossible, but imagine a service that earns money from ads and provides a service to convert images into PDFs. This service can be scaled this way, and you can handle as many requests...
