Yet most of these aren't needed for small crews... do I care that my DB is not HA when I have 1 RPS? You said yes, but I disagree. Do I need centralized logging if I have a few servers? It's already centralized for free.

It's much easier to setup and forget basic bare metal servers with PG/NGINX and whatnot, than it is to automate using dozens of AWS services.

People pretend that AWS doesn't cost engineers to run it, when it's IMO basically the same human cost, if not bigger as complexity grows. You just don't pay that cost upfront, but you sure do pay it later with interest.

You get stuff like HA but that's not free. You also now have to manage a new boatload of services, scripts, changing APIs, etc.

YMMV, I run a startup that serves critical customer use cases, and from day 1 I had to care that my DB was HA, backed up, and could be restored. Actually had a case early on where we had to test this because I accidentally deleted customer data and had to restore - took all of one click, with no scripts, no prior investment into backup management etc. We also had to go through infosec reviews from day 1, and many of these are a must have. Doesn't matter if it's a small crew or large. Our customers care.

3 years fast forward with hundreds of customers, and we haven't had a need to hire someone full time to "manage" these services. This may/will change down the line, but I couldn't have built my business without one of these cloud vendors.

Edit: I also know the pain of building (and managing) this on bare metal (last company did that) - and it was just apache/php/mysql on bare metal. It was a mess

I would definitely say that your use case for AWS is not just warranted but good. There are many use cases where going for your own servers or even data center (even "rack room" or "server in storage room") is a better idea, but this isn't it.

Not to mention compliance. If you have to go through third-party audits (and most businesses do after reaching a certain size), then using standard services from a public cloud provider can simplify things significantly. Sometimes that's because you can just offload "security of the cloud" to the cloud provider, and other times it's because there are well-established guidelines for how to achieve, say, PCI compliance on AWS.