The flip side to your comment, though, is that chess can be highly entertaining for people just getting started, who neither know any established openings or play lines, nor are playing against opponents who do... which describes the vast majority of newcomers to the game.

I would argue that you can get to approaching 1500 ELO without really knowing any theory at all, and just focusing on what "feels" like appropriate control of the board & game dynamics... and again, the vast majority of casual players will likely never move beyond that. But it's still fun, especially when they're able to challenge friends between classes to 3 or 5 minute matches.