If you mean connect remotely to a desktop that someone else is using on another machine, yes that is indeed a different use case.
Eg, my kvm (virtualization) host runs RHEL and no desktop environment, but I can easily run virt-manager using X forwarding over SSH when I'm creating a new VM and a GUI is easily than writing a domain XML
In face I've forwarded virt-manager to Linux, macOS (XQuartz) and Windows (WSL w/ X server)
However, this isn't why people want to use the "remote desktop" protocol. The app that I'm accessing over RDP isn't something I'm running after I connect to RDP: virtually all of the time it is an app that has been running for weeks and will remain running for weeks to come.
I am using my computer right now, after having woken up from a nap. This computer is doing all the things I left it doing when I went to take that nap. It has a bunch of state for all of these running applications, and if every time I walked away from my computer all of that state disappeared, I'd be annoyed, as I want to be able to sit down at my computer and do five minutes of work and then go off and do something else and come back and do five minutes more of work.
This is the primary use case for the remote desktop protocol: I leave a bunch of software running on my desktop and then I go somewhere else and I can remotely log in to my desktop and see all of my running programs. If I have spotty wifi and I only manage to get connected for 30 seconds before I get disconnected, I can just reconnect and everything is exactly where it was as I wasn't logging to run anything: I'm accessing things that are already running.
So, no: "at the end of the day" these are fundamentally different use cases, and the former use case simply isn't something I feel like I ever want to do. Hell: it isn't even what I generally want with a terminal! (I had always set myself up so I had running static screen sessions going that I'd remotely connect into, and then I use either autossh or a little bash function running ssh in a loop to reconnect to that remote screen session so when I open my laptop it steals my terminal from wherever I was using it last to my local display.)
The premise of remote desktop connections is something which kind of changes how you use your computer: once you try it and get used to it, you start to treat the terminal you are at as a commodity, as every computer not only has access to your files but every computer has the same state and let's you immediately jump right in to where you left off with your work. In contrast, I'd claim the use cases where you want to, while you are out, run an app on a computer you aren't at is a niche use case.