AWS/Azure/GCP is suggested because it's easier to hire someone who can maintain it after the founders burn out or exit, and most importantly because the VCs hav

AWS/Azure/GCP is suggested because it's easier to hire someone who can maintain it after the founders burn out or exit, and most importantly because the VCs have access to loads of free credits that can get you through the first year or two, effectively increasing their investment (and yours too). Nothing stops you from just running an EC2 VM there, this has nothing to do with microservices. I never had a VC ask me about software system architecture, though yes they strongly suggested we use AWS, which we luckily did. There are services on AWS that bring significant benefit even if your app is a monolith - managed DB, email service, queues, nowadays the ML things, and in the past DevOps pipelines and Git repos before that became free/available on GitHub.