They add a lot of overhead and require extra tooling to stay up to date in a maintainable way. At a certain scale that overhead becomes worth it, but it takes a long time to reach that scale. Lots of new companies will debate which architecture to adopt to start a project, but if you're starting a brand new project it's probably too early to benefit from the extra overhead of micro architectures.

Of course there are pros and cons to everything, don't rely on memes for making architecture decisions.