RDP is kind of limited

It’s useful if you only need to do stuff while you’re actively connected but you can’t, for example, remote in and start an app or process going and then disconnect and have that app continue.

Sure you can, I do this all the time on the work RDP server. Maybe you need to tweak your group policy so it doesn't kick you out right away.

When you d/c your profile is essentially logged out.

Nope, depends on what group policy you configured. If you've never configured that before as a starter launch gpedit.msc (with admin privileges) and head to Administrative Templates / Windows Components / Remote Desktop Services / Remote Desktop Session Host / Session Time Limits. The other settings in there are also useful for other things you may want to configure.

Your activity also can’t be viewed by a user on the remote system, if you needed to collaborate or assist somehow.

Yes this is true, the only way to do that is to have admin privileges on the host and then take over that user session. But of course that's not collaboration, that's just you taking a user's current session without them being able to see what you're doing.

On Windows the official way to do that is via Quick Assist (on Windows 10, not sure if it got renamed on Windows 11), it's sort of a shared RDP session where both the user and the remote user can share the same session. I've never needed to use it myself - with the work system users are pretty content with just having me "fix" whatever they needed without them watching, they usually don't care how to fix the problem themselves LOL.