If my experience is anything to go by - a good proportion of this will be people accidentally double clicking a .md (or other random text suffix), and cursing whilst they wait for XCode to slowly load enough that they can quit it and open the file in a proper lightweight editor..
I feel like the #1 reason to install Xcode is to get Git working on macOS. Yours is probably #2. I wouldn't bet money on iOS/macOS development sitting at #3.
Command Line Tools for Xcode is a separate smaller package than the full graphical Xcode tho: `xcode-select --install`
Yep, I open Xcode several times per year, but haven't done it on purpose since... uh, 2014 or so?