They do by enlarge yes, and often those same active players keep most of the old worlds ticking along to varying degrees ... theres Something called "Price's Law." (also known as Price's Square Root Law) which states that 50% of all work will be done by the square root of the total number of people who take part in the work.
Prices Law and it can also be applied who does all the complaining, crying and whining too .. so theres that ..
So 10 (10%) of the world population would make (50%) of the sales for Inno and or activity in FF etc. The other 90 (90%) people on a world would make the remaining 50% sales and or activity. Extrapolate this out across worlds and I think youll find roughly its the same results of the total player base mostly active in FF across the server and 10% or the players will make up 50% of all FF activity etc .. especially the older worlds where most casuals and one world players long since moved on or quit, often all thats left are the die hards and same FF base and or big spenders reluctant to dump so much investment.. its mostly the same players left now doing FF on all old worlds from what I see and definitely 50% .. just need to look at westforts and look, the data is all there for all to see.
We all say hello to or shoot at each other 1 hr to the next on the next world that same evening all the time... in fact more than 1 battle same time on multiple worlds has become very common and somewhat of a running joke. That prime time is for the same people to enjoy every evening hopping from one world to another just doing FF while the other 50% never get an online battle. Some alliances even try to stagger their calling to suit in order to facilitate this, just another strategy the most active FF players have learned over time, but ofc it dosnt make much fun for the other 50% who live lives outside these prime times. Thats possibly also another reason FF number drop off now so fast on new worlds... id not bother at all if i could only ever be offline at battle times due to where i lived or job etc restricted to just 8pm - 11pm sever which has always been prime calling time .. but to have all in this time period imo is very bad news in the longterm, Colorado at least has learned this over time hence its popularity still and reflected calls sometimes way outside of prime.
The only 1 true exception i know of is Colorado where players move about all the time and its a managed system but then its still the same 10% of players doing all the work making sure of that and kudos to one and all there for so much effort over the years to keep it so active for all. So Price's Law still applies.
Merging worlds would i suspect become very problematic with so little player base left now, it wasnt before with 10,000 on them when worlds closed as in the past. ofc no one would notice so much with a vastly bigger player base .. now many older worlds have just 500 or so on them now to make any difference youd have to merge half a dozen worlds to make it worthwhile as always its diminishing returns and lots of wastage. Approximately 20% would vanish as dead/neglected accounts and probably 50% on more than 2 being merged leaving choices of which toon to keep and what to dump... so thats another few hundred accounts also lost by deletion ...
Lets say 6 worlds got merged 500 left on each world so total 3000
Naturally deleted 20% 3000 = 2400 left
Multi world players - 50% of 2400 = 1200 left over 6 worlds ... thats not really much of a healthy world base left but at least it might be uber active for a while.
Just opening migrations or merging at this stage might well for Inno possibly make far less revenue when that same Prices Law works re who spends on each world etc is taken into account. Inno ofc are trying to manage the decline thats all and max its $ to cost ratio.....and ill wager Inno know this too and all about Price's Law.
Any old world that has a an alliance which owns all forts unless its about to close anyway and keeps them instead of immediately dumping at least half is doomed to die fast as we all know .. ( The only methods ive seen actually work )
As a perfect example. El Dorado and Houston, two im on which im aware are like this .. it dosnt matter why how or who, only it is currently this way. If your in such a group or town leader of etc once a world is totally controlled and do nothing about that but simply gloat instead of vacating all forts or disbanding / splitting the alliance up right down the middle allowing for a total reset or something as drastic ? then your a total njub and deserve the coming wasteland you have created, not migration in order to repeat the same mistakes elsewhere
... this was where multis use once came in too, that worlds would not become easy to control, own and were I think a failsafe, to allow the dynamics of the game to shift as they once did, unlike now. The loud whiners and ticket makers about multis ofc are only the same 10% prices Law not the other 90% of players who chug along happy regardless.
A few people might now prefer a safe environment and sanitised The West but the vast majority of vets and this games once 100 x + popularity say it was far better with less rules, more multis and total chaos allowing for things now impossible on this fast now dying game.. shame but all things end.