I think it comes down to the fact that at the end of the day, your software runs on real hardware, which isn't perfect. So rather than hide these imperfections behind an opaque surface, AWS let's you peek behind the scenes to optimize your software, debug issues, etc. It's really useful if you're working at a large scale.

They also have things like Lightsail if you don't care about the details and just want the packaged solution.