I’m still wondering when Nikon will announce their medium format camera. The Z mount is suspiciously just big enough to accommodate a 44x33mm sensor, and Nikon has already made lenses with a 55mm image circle (such as the PC lenses).
There are so many amazing lenses from Nikon F mount, I doubt we’ll see many of them again in a Z mount version. For example, one of my all-time favorites is the 200/4 AF micro-Nikkor…I also love the DC lenses, the 180/2.8 lenses, the 50/1.2, and so on. With F-to-Z adapters, there will always be a market for these because they last forever.
One good thing about old lenses is their simplicity, provided the elements don't delaminate and you avoid physically damaging the outer elements then they're pretty serviceable and aren't reliant on motors and electronics to work. Motors and electronics which will deteriorate and stop working at some point and for which spares are probably not going to be available. In fairness we should keep the problem in perspective and AF lenses can last many decades working perfectly well, but if anything does go wrong they're a lot less easy to service or repair than an old style mechanical lens. Keep an eye out for fungus and address it early and avoid using them to hammer nails in and you shouldn't have any issues.