I feel like you don't understand the problem. It's not bad that realms can have 1 noble hold a region by himself, it's that their aren't enough nobles for all these lands, hence the freezing and rogue invasion.
When realms have more nobles than regions, they aren't telling knights to screw off nor are knights going I need a lordship, I am out. We just don't have as many players so we don't have as many nobles. The increased density should end boosting fun in a variety of ways that can't always be seen by some immediately but some I talk with are understanding. It's not the end all, perfect fix, but helps a lot and more is constantly being developed to aid the game, but it takes time.
I do understand. But one problem is density, another is recruitment and retention. Eliminating regions will certainly increase the density in the short term (it already has) but it's far from certain that this will stick in the long term, and we could potentially be right back where we started in a few months but on a smaller scale. Requiring more nobles to hold a region doesn't address the retention problem, but it would address the density problem in a more sustainable and player-driven way.
As for the retention problem, my personal view is that the game doesn't do enough to hold the attention of new players. It's not that they're shouting "give me a title or I'll quit," it's that apathy sets more quickly for new players and they simply don't feel the same motivation to log in every day or every week the way older players do. For old players, logging into the game is already part of their daily or weekly routine and they'll keep playing for some time even when the game becomes stagnant. New players, on the other hand, will have far less tolerance for boredom. And I think the easiest way to address this is by giving new players more to do.
