It's frustrating that Apple doesn't have their own Screen Sharing (VNC) application on the iPhone/iPad, if even just to provide a basic screen-sharing experience. They have something builtin to FaceTime (that I've never tried) as a kind of remote-support app.

RealVNC did not work from iOS/iPadOS to macOS Golden Gate when I tried it relatively recently, although it may have been updated since. It's possible Apple changed something in their version of VNC's auth.

I used to recommend Screens (v4) when it was flat licensed, as it seemed to work well and was well designed in dealing with smaller screens and input differences. Now (v5) it's $5/month $30/year $200/lifetime, which I can't really justify for my casual use case.