I used my D750 from 2014 to 2021 to shoot my part time real estate work, in its time a fabulous camera, probably underrated ...
In 2019 I got a Z50 and DX 10-20 for f mount to serve as a backup and also go up on a pole which can be really useful shooting exteriors of properties.
The mistake I made was getting a Z6ii 6 months later. I was patient enough to wait out the original Z6 which had famously skittish AF - until the 6ii came out which I thought was going to fix that. I know plenty of folks did/do fine with Z6s and 7s, but I can show you far more shots with questionable focus from my Z6 than the 750 ever came close to producing.
I wish now I had waited all the way until the Z8 finally appeared (which I now own). But there was no way of knowing what was coming, even after the Z9 appeared. Even now my Z8 will occasionally confirm focus - but it's not there - and this is on tripod and completely static subject matter. It's far better than the 6 was, but not as rock solid as I think it should be, even now with firmware 2.0
The truth is I gained very little moving from my 750 and my 14-24 2.8. into Z.
I kept the 750 all along, sold the Z50 when I bought the Z8, then sold the Z6ii, and and now I just consider my 750 to be a perfectly able backup for my Z8 ... I expect these two cameras to ride off into the sunset with me.
I'm 74 and if I can do 5 more years of this kind of work, I'll be really lucky.
P.S, I guess by example I'm trying to say I already knew what the content of the video asserts. Shame on me for loosing my nerve. It cost me the lost delta on a Z50 and Z6ii.