Absolutely, and unless you're riding a roller coaster, you can always grow your team with demand. When your operation has grown enough, you can shift from consultants to employees to save money and get the knowledge into the company, you don't have to start with a team of three to manage one server.
Exactly - and good consultants/contractors will still provide you with the in-house docs/guides/configuration management that will help you either transition existing, or hire new staff when the time comes.
Yes, some places will need a full time team of multiple people, but a lot of places don't, and can get a tailored solution to suit their needs perfectly, rather than just trying to fit into however it seems to work best using the soup of rube-goldberg like interdependent AWS services.