This is the advice I give early stage startups... don’t waste cycles learning the AWS stack, and getting locked in. Just pay for a cheap VPS, and scale it vertically as you grow. By the time you outgrow vertical scaling you should have the revenue or funding to figure out your at scale architecture.

You’d be surprised how much you can handle with a single beefy VPS or dedicated.

Yup. The other aspect that surprised me is how crazy the relative costs are.

I'm paying 7USD for a 16gig/4 core ryzen I snagged on a special. That's a good 10x off from what big cloud would give me.

...down side is it needs to be engineered for "provider may disappear overnight" so backup strategy needs to be on point.

A slight twist on this is a cheap, beefy colo box with nothing installed except something like k3s. This way you end up with all the YAML bureaucracy paid down in case that dreamy future with millions of users finally manifests

Had a VPS for side project at Vultr. First step first, could not send sign up emails from it.

Sounds like the problem was with the networking or application code. VPS can do anything when it's configured properly.