Considering the ZF and switching to mirrorless. A few questions/holdups

I have been shooting with a d800 for years. Have been hesitant to move to mirrorless but seriously considering the zf. I absolutely love the Nikon retro models (used to have a DF for years). Beside them not having a silver version, it seems to be exactly what I want.

I mainly do product/object photography and I only shoot manual focus.

My holdups:

• It feels weird to upgrade after all these years from d800 and not really gain any megapixels. Thoughts on this? I'm torn between the ZF and D850 (which has nearly twice the MP)

• I mainly use older AIS lenses. I know for the ZF I would have to get the adapter. Does the adapter degrade images at all or cause any other issues?

• Stupid question, but is the ZF a decent pro/studio camera or is it more of a travel type camera? It's hard with the vintage look to know who the target audience is.

• Finally, how will these hold their value? Is there a chance of a replacement model coming out any time soon? Tough knowing what a good deal is buying a used kit.

Thanks!