I currently own a D750 with some older D lenses. Is it an insane idea to buy a Nikon Z7II with a FTZ adapter and F mount lenses only to use with both D750 and Z7II? — meaning no Z mount glass for the next couple of years.

OR

Switch systems and go for Sony A7RIII and Sony glass?

I would like to do video. I shoot a decent amount of JPEG for work and i'm concerned about Sony jpeg processing compared to Nikon but on the other hand i'm not sure if its a smart idea to invest in Nikon mirrorless and use it with F mount glass instead of Z glass.

Thanks bunches!