I agree, I deliberately generalised with those examples to make a little clear that as the required traffic, capacity and risk increases there's a lot of benefi

I agree, I deliberately generalised with those examples to make a little clear that as the required traffic, capacity and risk increases there's a lot of benefits with using services that automatically configure and provisions load balancers, network routers, machines, clusters, etc for you. This is not to say that it's a "one click configuration+deploy with no security issues whatsoever" , but depending on the clients you work with you may be rightfully forced into using a cloud provider and hire DevOps engineer to manage the infrastructure.