Why many startups start with a monolith
A well-structured monolith is often easier to ship, easier to test, and easier to understand in the early stages. That can be a strong fit when the team is still validating the product.
When microservices become useful
Microservices can make sense when the system has clear bounded domains, independent deployment needs, or a team structure that can support the extra complexity. They are a tool for the right scale, not the default answer.
Pick the simplest architecture that can still grow
The goal is not to be clever. It is to build a system that stays understandable while the product gets larger and the team becomes more distributed.