I have not yet made the leap to mirrorless, so no experience with RF lenses.
I suffered the repeated depreciation in dSLR generations as the technology matured. And as exhibited by the R vs. the R5/R6, the technology in mirrorless continues to mature. I have merely opted not to suffer the depreciation losses thru multiple mirrorless generations of evolution, but to wait for slowdown in evolution befor jumping in with both feet.
IMHO, mirrorless is 'different'...it is an alternative way to capture an image. The technology enables certain advantages (such as eye tracking of both humans and animals), but so far those advantages over dSLR are not essential tools for the kind of shooting that I do, Ergo, I can wait for further technology advancement before buying in and accepting a new round of gear depreciation. Not being a Luddite and refusing the technology, merely being wiser after enduring more than 10 years of dSLR evolution...spending money more wisely than when I could earn a new camera in half a month of discretionary income or less.