Yes, desktops are pretty much only popular among the PC enthusiast/heavy gamer crowd, as well as heavy production studios like LTT these days. Most of the normal folk, average gamer, don't even bother considering desktop computers.
You are correct, notebooks have come a long way since the original ones in the late 80's, and throughout the 90's. I still remember when notebooks didn't come with built in bluetooth and WIFI adapters, they required dialup modem connection, or ethernet connection.
Now days with WIFI AC and WIFI 6, as long as you have a router that supports those standards, then they get to be pretty much nearly as fast as a hard cabled connection. I love notebooks, they weigh so much less then a desktop, take up less space, and are just overall more power efficient.
My MSI GE76-231 Raider notebook is a high end gaming machine and it uses a 280 watt power brick, which is far more power then most notebooks on the market. When you consider most thin and lights use 40 to 60 watt power bricks, its obvious those are most certainly more effecient then your average 500-watt desktop computer lol.
Mid-grade gaming machines generally use 160 watt power bricks, which is still less power then desktops. And forget about buying pre-built desktop computer's today. Yeah, I been watching Gamers Nexus with Steve Burke, and I can tell you right now, its horrifying, lets just say that.
Notebooks are where its at. Love notebooks!