Tephra has summarized it overall beautifully.
To add on to it, Officials are hosted on GPortal servers. Having hosted my own server in the past and discussions on servers in general, GPortal is not only a poor service provider but I would hazard as well that the package utilized by Funcom is a lower tier.
Region and platform is a factor of course; I’m in NA East and have played on all modes but PC PVP being most played and preferred. I should mention as an aside that I was a 5+ hour per day Official PVP Player for about 3 years straight. On weekends I would play 10+ hours per day.
Prior to the ages there were several active PC PVP Officials, often capping. The popularity of a server would be dependent on who, what, why. Migration always common to a degree. Population significantly dropped off over time due to a variety of issues.
Out of curiosity I logged in to see numbers. 1530 and 1540 being the most popular NA PVP servers for years and 1530 is capped with a queue of 6. This tells me there’s drama there; more than likely meme type brigades with a splash of cheating and puppets holding spots. 1540 lagging behind with 34, so probably those who don’t want to queue are going there. Fairly normal behaviour in the last 6 months or so.
But while PVE has a “primetime”, generally I find that it rarely caps in the past year. A west having the highest at 18 currently. So Tephra being right that once you hit about 15+, the server suffers greatly. This is in large due to unmitigated building - placeables that GPortal and the game in general not being able to handle.
In the past, again as a PVP player, it was common for a server to suffer at 20+ players but not to the point of being unplayable. This is in large part to the overzealous use of Zendesk removing builds. That still doesn’t stop the problems since Ages. Al-M being disturbed means that everyone feels it within about a 5 square radius. Simultaneous raiding in general, summoning gods, raiding thick builds, etc.,… is obvious to all. Anyone logging in to a resource intensive base in all modes, is felt as well.
I haven’t logged in since the BE fiasco started - seems to have been fixed? Prior to that I was on 3 PVE servers and generally they didn’t hit 10 ish players during primetime.
I didn’t really have much issue personally with resource intensive builds but I did stutter and die A LOT during purges initiated by other players across the map.
IMHO Funcom should upgrade or change the server service provider - however, as is alluded to based on advertisement and previous discussions, it would seem that there is a contract that can’t be broken. Barring that, doing server merges, inasmuch as that might negatively affect the very few playing on low pop servers and/or serial refreshers, it might be necessary.
So ya… mostly a PVP perspective.