Lemme lead by saying that I agree with a lot of what Polar said, but am not entirely on the same page. Doubles is definitely the superior format for players who like to strategize and really think about each individual turn. Because the format relies more heavily on team synergy than singles, typing and move pool are taken into consideration a lot more than "this thing hits hard and gets stealth rock". The broader use of protection moves, priority, and prediction give Doubles its unique flavor.
Meanwhile, things like VGC operate with a noticeably wider variety of pokes involved, less exploitation of singular aspects of battle (hazards, baton pass, stalling) and honestly, just to greater entertainment to watch and play.
Doubles, especially VGC, definitely has its own set of common offenders. You can expect to battle about approximately 1 million each of Suicune, Zapdos, Mega Kang, Lando-T, Terrakion, Heatran, Mega Mawhile, Arcanine, Sylveon, Amoongus, Breloom, Hydreigon, Aegislash, Clefable, Politoed, Ludicolo, Mega Metagross, Mega Salamence, Zard Y, and Mega Venusaur in a given week. You can also pretty reliably count on speed control, weather wars, Fake Out and Fake out predictions, redirection and deflection, Heat Wave and Rock Slide after Heat Wave and Rock Slide, Pranksters, Perish Trap strategies, Trick Room, etc. Just like any other competitive play, VGC awards innovation as much as it does raw power. Zach Droegkamp (Braverius) and Angel Miranda are two great examples of smart players who innovate, but they both also run the top level threats.
tl;dr I think people just like what "they were raised on" and that's singles, specifically OU.
Naaaaaaah. People were raised on original 150 Gen I in-game play. It's night and day from Singles OU. Remember how hard Brock was to beat because his Geodude would set up Stealth Rock, hang on with Sturdy, and then Self-Destruct? Yeah me neither. Smogon is a flavor. VGC is a flavor. Both are far from perfect and feature broken Pokemon, because gamers aren't necessarily the most creative bunch and like to use powerful stuff.
In all seriousness, I think that a perfect meta, rather than punishing the use of a couple dozen Pokemon and making tiers for a certain generation as a windfall for underused mons, would have a revolving door where the most popular pokemon are periodically rotated into the ban list so that people continue to innovate. I think a quarterly system like the one used in VGC would be ideal. Last quarter's ban list would become legal again, and because at least part of the previous quarter's ban list was integral to their use in teams, it would introduce new team synergies and force players out of the box.
I would also think it would work best in Doubles, which encourages team synergy.