Many photographers have made the switch to Canon's recently fleshed-out ecosystem, but that might not mean they have sold all their glass. Instead, there are many options for adapting Canon EF lenses to the new Canon RF mount. Here is a comparison of the three official Canon adaptors.
Whenever you move to a new camera system and mount, you have the dilemma of whether to sell all the glass you have acquired that no longer fits and buy lenses that do, or to adapt the old lenses. I have had this dilemma a number of times over the years and I'm confident that I made the right decisions each and every time: adapt.
If you can afford to lose a significant wedge of your hard-earned cash, then by all means go ahead. However, be aware you are almost guaranteed to lose money, even if you bought the lenses second-hand. This is particularly true if there is a sudden mass migration towards a new mount of the same manufacturer, as has been the case since the release of Canon's R5 and R6. Their first two mirrorless bodies were by no means bad, but the latest two have seen a lot of interest from professional and enthusiast photographers alike.
If you decided you can't quite justify parting with your old Canon EF-fit lenses, or you can't bring yourself to part with your favorite glass (for me it was both!), then you need an adaptor. While there are multiple EF to RF adaptors, Canon themselves have three (technically four), though they have been infamously tricky to get your hands on. Here are your options: