Like you just identify which service it is you want to exploit, then all you do is pick the relevant metasploit module and next thing you know you’ve got a reverse shell as local system.
The thing that you’ve missed in your argument, is that enumerating properly and knowing what to attack is a huge part of the entire process. It’s not something you “just” do. Metasploit makes some things easier but doesn’t make the most difficult parts of hacking easier. It’s convenient but you need to know what to do in situations when the off-the-shelf tools don’t work.