Are all competitive multiplayer games unfriendly to casual players?
Hope @Johnway doesn't mind my making an entire thread out of something he posted elsewhere. But this sounds like something that it would be good to get a lot of opinions on.
My personal opinion is that the answer is a wishy-washy yes. There's no doubt that you get better at a game the longer you play it, even if you don't notice that you are improving. This happened to me in Vermintide 2. I was barely able to complete any level on any difficulty setting when I first started and ended up soloing Legendary in the end. So the people who are playing these multiplayer games constantly are going to improve over time.
But the other side of this is the level of skill that a game requires and the natural talent of the casual player. Some of these games are low skill games. You still need to be good at shooting and strategy, etc. but there's nothing in particular about the game that takes practice to be able to master. The shooting or melee or whatever is just generic and doesn't ask anything special from you. It's been ages since I played a competitive game, so I can't give good examples, but For Honor was a game that took a great deal of skill specific to that game, so newcomers or casuals were at a severe disadvantage.
But the last part, the natural talent, has a huge impact. I started gaming with my son when he was 4-years-old, and he's just become a remarkable player, much better than I ever was. For him, he can buy an old game that still has a strong player base, and he can be immediately competitive. The very first time he played Chivalry 2 a couple of weeks ago, he was fantastic, and this is a game that has been out a little while. If I tried to play Chivalry it would be a painful slog at this point. I'd get beat every which way for weeks before I would really start to get the hang of it, and that's only if I played it regularly.
So I guess my answer is that yes, every game is unfriendly to casuals, but some more than others, and there are always a few casuals out there who break the rule.