After going through a number of articles on this topic, I am ready to stop.
For most users, there is almost no point in using coaxial cable for Ethernet.
The main issue is cost. After that are installation, maintenance and efficiency. The CAT55 cable is more than enough for anything anybody would want.
Well, some special devices might need coax, that that is very limited. My Oscilloscope requires coax. But that's outside ht range of this topic.