Once I was working in a quite small company (around 100 employees) that hosted everything on AWS. Due to high bills (it's a small company that resided in Asia) and other problems, I migrated everything to DigitalOcean (we still used AWS for things like SES), and the monthly bill for hosting became like 10 times lower. With no other consequences (in other words, it haven't become less reliable).
I still wonder who calculated that AWS is cheaper than everything else. It's definitely one of the most expensive providers.