Please let me know what you think.
I think that's some basic vanilla **** playstyle, which is fine, but describing it as a "your style" is kinda exaggerating.
This gameplay also shows why the snowball is not really an issue
TW added heavy anti snow balling measures many updates ago now. The issue now is more the potential stagnation and repetitiveness of mid/late game because of the anti-snowballing measures.
I create a YouTube playlist where I show my playstyle which shows how to gain control over the entire map in about 10 years at the hardest difficulty level with no exploits.
I looked at the last 2 videos of your playlist and I'm seeing very colorful map, it does not appear you gained control of the map. I would say you are still in mid game, you have a growing faction and are doing well, but you have yet to encounter the war/peace stalling your own vassals can do as you faction starts to become very large. Now whether that faction will take the map in the next 10 years, who can say? However the issue is more with the lack of satisfaction and interesting gameplay many plays report during this part of the game.