I write C++ business API servers. On the type of hardware I rent from Hetzner /OVH they're capable of processing thousands of requests per second. This would cover probably 90+ percent of real world businesses.
>"an API for everything"
Not sure what you mean here. API for what in particular? My servers talk to partner systems of real businesses. We consume their APIs and they consume ours. Integration is done by little plugins that translate requests should it be needed. I am not sure how Amazon will help in this department. The only generic API that everyone uses is email but you do not need Amazon for that. As for database - I always deploy one local to my business server.
>"good customer support"
Frankly in many years there was like 2-3 times when I needed something resembling support from Hetzner / OVH. In either case the response was prompt and satisfactory.
There are many use cases where hosting fee is not the right thing to optimize for.
> Not sure what you mean here.
I assume referring to APIs for controlling and monitoring the infrastructure, not anything about APIs you may provide in your application or consume from external sources.
Old-school dedicated servers are so cheap that you can match a startups' peak autoscaled load and still pay less than their "idle" load.