Fully agree that mirrorless is the future, took long enough to fully get track.
There are some DSLR snobists, there are prime lense snobists, there are mirrorless snobists, there are frame rate snobists.
In the end the picture matters, whatever helps you get good pictures is good for you.
That beimg said, as of now I'd say a Z6ii is still behind a D780 a bit and quite a bit behind a D6 (I'm a Nikon shooter, so don't ask questions about other brands). A Z9 on the other hand... That being said, none of those options beats the one you can actually afford and know how to use.
Edit: Which DSLR (Edit 2: I mean mirrorless...) gets 20 fps? The Z6ii is at 12. Everything above is, what, 5k plus for the body?
Edit 3: That seems to be Nikon's Z9 with 20-30 fps in continous mode. Up to 120 in small JPEG. Impressive, and with 6k Euros almost reasonably priced when compared to other Nikon top mofels of the past. One can still get a Z6ii and a bunch of top notch lenses. Damn, I shouldn't have looked it up...