>>45115781>Smogon is better for playing, but VGC is better for watching.Pretty much this.
However, I will say this as a person that plays and watches both a lot, singles because very entertaining to watch if it's a player explaining their thought process as a match is happening ie showdown lives like Blunder and Pokeaim.
I love watching that kind of thing, because a very big difference between the two formats is that there is very rarely ever an absolute best play in singles so there's a bunch of different ways to approach a situation that may differ from what you may have done things that completely changes the flow of the match.
It's also fascinating to see a player explain a game plan at team preview and slowly work towards it over lots of turns and then get into a "checkmate" position that doesn't really seem game winning at a glance. Like for example some 40% chip they got on Heatran on turn 35 was actually the "checkmate" that lets them win when X thing sets up turn 45.
VGC is definitely the better spectator format though because of how quick and bombastic it is, and you need to know a lot about the meta to enjoy watching singles in the way I described while VGC has way more broad appeal.