Very true.
I am somewhat an expert on this matter as I have a son who is permanently in a wheel chair and I need to own/rent vehicles which he can get into and out of without too much difficulty.
First, seat height is the defining criteria as opposed to just height above the ground. Second, how far the seat is from the edge of the vehicle is very important. This second point kept me from buying the SRX in 2004. (they later "fixed" this problem)'
The width of the door opening is also important as you have to be able to comfortably swing you legs into the vehicle.
I have a wooden template that allows me to measure the seat height above ground. It is also marked to show har far the seat is inset.
From experience, the only way to be sure is to actually get into and out of the prospective vehicle. DO NOT rely on responses you will get online as these are not tailored to your specific situation.
Go check it yourself.
From your post i cannot tell if you thing SUV height is good or bad for older people. . My experience says if they are not too short SUV is better. As an 80 year old with mostt friends in the same age category that is a fairly wide experience.
George