the a6500 is an outstanding camera, and if I had it I would not have upgraded to the a7r III. Yes, the two are said to be in completely different leagues, but the a6500 is far from lacking anything major that would hinder it from capturing the same images as the a7r III. I actually still use my a6000 for filming. I will say that having a full frame camera is pleasing to clients, but that's irrelevant. The biggest benefit I've seen with a Full Frame camera is the ability to naturally capture more crisp photos (the margin of error decreases), this is probably due to the larger sensor's ability to capture more light.
Ultimately the camera doesn't matter, it's purely the photographer. I don't typically share with people which camera I have because it can be discouraging and sometimes disingenuous ... it's people sizing you up. #justgoshoot if the frame is ill camera is irrelevant.