I've always thought worlds was weird because it's in the middle of the touring season. To say you're the world champ then having more tournaments just seems strange. This is why I've thought of the USDGC as a more prestigious event.
Or a little before the middle, in this case. It's sort of the 2016 championship, because entry is based on 2016 play. I suspect this is tradition---like the more-rounds was---which evolved because when World began, there was no real "touring season", or organized tour.
I wouldn't consider the USDGC
more prestigious, but it was almost
instantly prestigious for more than just its spot on the calendar: from the beginning, it was event you couldn't simply sign up for, but had to play your way into. Until recently, a duffer like me could play Pro Worlds, even Open, if I wanted to, but except when they offered sponsors' spots at the USDGC, there was never a prayer that I could play it.
I expect Worlds will always be the most prestigious title---not to everyone, but to most, and particularly to the players competing for it. But there are a number of ways it could change to differentiate itself from other events, in the future. Doesn't have to be 6 rounds; could be even more epic courses, or small fields where only the best qualify, or big payout, or something else.
This all isn't unique to disc golf, though. Golf's most prestigious events aren't at the end of the season, and aren't dramatically different formats than other events. Nor auto racing; NASCAR basically
starts the season in Daytona, just another race. Nor, as I understand it, is tennis. Those are "championships", of course, but they are prestigious.