springrollsi absolutely guarantee you if you asked most casual players what's the biggest barrier to entry within competitive tf2, there answer would be either "I can't play my main class full time" or "I don't want to play 5cp all the time" (ignore viaduct)
Agreed, although their first response might be "there are TF2 leagues?". Research into TF2 player activity has shown that the most popular maps that bear any resemblance to the "proper" game mode are ones like 2Fort. Bizarre gamemodes like low-grav cp_orange have far more players than any competitive format. This is without looking at how many people are just trading and don't even play the game. By contrast CS players play 99% defuse maps competitive game mode, directly relevant to the competitive game.
The casual community is so massively fractured across so many different maps and game modes it's impossible to adapt the competitive game into a relevant format without it becoming a total meme fest. Which week is vs Saxton Hale?
I really think the competitive community is best served by trying to stick to what is the most fun way to play and stop worrying about the public appeal of the format, there is no magic format that suddenly makes casual players care because they will never care. It's just the wrong game for it, not because it's not a high skill ceiling hard core shooter at heart, but because the development direction has been completely anti-competitive for 10 years and they are never going to reverse that trend.