What is AXVisualSupportAgent, and why does it eat my RAM?
I don't know what the process does but this reference has a description of a way to prevent it from using a lot of cpu time. The process is related to the accessibility settings on your computer. To reduce the time taken open system preferences and click on accessibility. Turn off the zoom function and turn off image smoothing. There are other things listed in the link. The link is originally in Japanese but the googletranslation was pretty good I think. It was also mentioned that the problem really started with Catalina.