Emerald Dream has an ongoing world pvp event system as a server: World War Emerald Dream 2019 My own experience is that regular player driven events like that tend to grow a much higher than normal pvp player base for servers engaged like that.
For example, back in 2007 when my own guild used to be in something called the “The Guardian Wars” on the Guardian server of City of Heroes/City of Villains. On the regular war night, player participation used to be about 60% of the players online, at the time of the event. In COX, you could literally run a scan for in that game as a player.
I think that higher server community investment gives you higher than average pvp player numbers. However, even passively, I do think that the balancing seems to be working overall.
My 2 cents. Your mileage may vary.
/salute