i mean, i would expect the most populous ship to have an easier time finding pugs than smaller ones, and Ship 2 is demonstrably more populated than 3.
At the same time, PSO2 is set up in a way that unless you are struggling to fill up UQs on a regular basis or the lack of players leads to a poor economy, population doesn't really matter. At least that is how it feels to me, as someone who has been on Ship 3 since Xbox open beta. I've not had an issue with finding groups for things, even at off-hours. If anything, the amount of times I've turned down group requests is actually starting to bother me lol (I prefer playing alone over playing in groups, so even if someone asks me to join a Divide Quest I often turn them down and then run it anyway....)
Also, while I don't have characters on other ships, Discord and Twitter are littered with complaints from Ship 2 about dead content and screenshots of undergeared players joining UH groups lol. It's a bit silly to hold up personal experiences as irrefutable proof that ship 3 is dead. Like, I'm sorry OP couldn't get the games they wanted here and I'm glad they found a ship that works for them....but the only time I had trouble finding a group for something I wanted to do was Space Magatsu during the last week it was up, and that's probably because it sucked and had bad rewards So I can't really relate.