I'm not saying it can't be done cheaper or more efficiently on simpler providers or even self-hosting, but you need the expertise and time to stand up the foundation of a secure platform yourself then. For example, AWS Secrets Manager is just there and ready to code against, as opposed to standing up a Vault service and working through all of the configuration oddities before you can even start integrating secrets management into an application. If you already have a configuration-in-a-box that you can scale up, then more power to you.
Your use-case of running a web service that is written in a very efficient language like C++ is not something you see too much these days. While it would be nice if most devs could pump out services built on performant tech stacks, our industry isn't doing things that way for a reason. Even high-prestige companies with loads of talented engineers only build select parts of their systems using low-level languages.
>"Your use-case of running a web service that is written in a very efficient language like C++ is not something you see too much these days"
In some place including big ones it is very much being used.
>"our industry isn't doing things that way for a reason"
I think the real reason is - the slower your stack the more money you will pay to Amazon, Azure, Google or whoever else. And by way of advertising, trickling down to education and lots of other means they make sure that this is what everybody (well most) uses.
>"using low-level languages."
Since when modern C++ is "low level". It is rather "any level". I compared my C++ server code with the similar ones written in JS, Python, PHP etc and frankly if you skip standard libraries C++ code can end up being actually smaller.
Your use-case of running a web service that is written in a very efficient language like C++ is not something you see too much these days. While it would be nice if most devs could pump out services built on performant tech stacks, our industry isn't doing things that way for a reason. Even high-prestige companies with loads of talented engineers only build select parts of their systems using low-level languages.