I think there are a couple more things to throw into the discussion here. In this case I speak for myself.
Photography for me is my number one hobby, and the more time I can spend doing it, the happier I am exercising that hobby. I've been at this for years, and over time I started focusing more and more on wildlife photography. I always used to use prosumer Nikons, certainly not the flagships. Initially it was APS-C cameras because they were lighter, smaller and cheaper. Started with D70S, then the D90, D7000, D7100, and ended up with the D7500. Until the D7500 I didn't have much interest in fast action wildlife shots - I was happy with more sedate, portrait-type images of the wildlife.
At that point Sony knocked the ball out of the park with the subject tracking and frame rate built into their A1. This then woke a desire in me for animal action images, BIF shots, etc. I guess I was ready to evolve my wildlife photography to a new level. Then came the Z6. It was as small and light as the D7500, it was full frame, and I decided to get one of those (traded the D7500 in in the process). The Z6, and subsequently the Z6II, were not really better for tracking fast movers than the D7500, so that was a disappointment. BUT - I was very pleasantly surprised by the image quality of the full frame Z6/Z6II. Such smooth, colour-rich, creamy, noise free images compared to my prior APS-C cameras.
Then came the Z9 that had everything I needed except it was large, heavy and way too expensive for my hobbyist budget. I waited, fully expecting Nikon to eventually launch a replacement for the D850, which was a very capable wildlife camera in its own right, at an affordable price. The Z8 is that camera and I immediately ordered one.
In summary:
1) The subject tracking technology incorporated in the more pro-level mirrorless cameras is way better than what exists in any DLSR. Is that a reason to move on from DSLR? Only if that subject tracking is something you need for your style of wildlife work. Five years ago I would not have seen a need for subject tracking, but now I need it because that's where my hobby is taking me.
2) Hand in hand with subject tracking goes a high frame rate. Shooting many shots of a moving animal affords one more chances of capturing that perfect pose and wing position.
3) The focus accuracy in mirrorless cameras is better than that of DSLR's. All my F-mount lenses are sharper on the mirrorless camera than on the DSLR.
4) The benefits of the EVF in the mirrorless camera are numerous. I like the fact that I can see and do almost everything in the viewfinder than what is possible on the monitor on the back of the camera. The ability to see and judge exposure live in the viewfinder before taking the shot almost makes the need for test shots obsolete. And I can leave my reading glasses at home when I go shooting.
The above three points are my reasons for upgrading to mirrorless. If these are not important to you, I don't think there would not really be much reason for you to jump to mirrorless now. I'm pretty sure there are many folks on these forums who still use DSLR's, and they will still be there to help with advice on any technical matters related to DSLR cameras. Every time a new, capable camera is launched, that steals the limeligh for a while until something new comes along again. The way of the world......