Welcome to the trials and tribulations we had in the 1990's Fd to EOS era, at least we now have EOS-RF compatibility and adapters unlike back then when the FD was a true dead end.
I was actually thinking of this reply before I saw your post, but it really coincides with my thoughts....
The funny thing is, that with mirrorless cameras (I have a couple now, the Canon R is coming for me at some point too)...one of the really FUN things I've found about them is, the adaptability for older, vintage manual lenses.
If it has manual focus and aperture, you are pretty much assured of being able to use it on ANY modern mirrorless camera as that there is surely an adapter for it.
Even the old Canon FD lenses....you can now use them on most any camera, even the RF mount, whereas it wouldn't really work with EF.
Hell, I've been keeping an eye out for a Canon 85mm F/1.2 FD lens for a few of my cameras, that thing was a VERY good lens and still is by most standards from what I read about it.
But that makes me wonder what will happen to the EF line? Most of them don't have manual aperture, and some of them have focus by wire, not mechanical.
What happens to the market for these a decade or more from now, when the newer cameras stop bothering to put in protocols to electronically change the aperture and focus?
Mirrorless cameras are making lenses 50+ years old viable options again....somehow, I don't see the fine EF line faring so well over the coming decades.
I dunno..will someone bother to take the glass out of them to do something, or rig and rebuilt the lenses so you can focus and change aperture manually?
At least, that's my thoughts.
If that's the case, it might be prudent that while you can feel safe saving and using them with your RF cameras for the next 5-10 years...around that time, you might need to seriously consider unloading them and getting what money you can with them, unless you plan to keep your EF cameras going till the just wear out.
And when that happens...well, those EF lenses might look good on a shelf or camera museum, but they may not actually work on anything, which is a shame...they are good glass.
Just my $0.02,
cayenne