During EA it’s easier to make global changes. For example, if it’s needed to create a new galaxy object for exploration it might require galaxy regeneration. In early access players should take this into consideration, they are ready for big game breaking changes which might require a partial/full reset of their progress. After the early access it’s harder to make something like this without losing players (harder ≠ impossible).
What do you mean makes it fun? Is going for months without a major update your definition of fun? The point of Early Access is to test out new things, and changes can always be reverted because it’s Early Access, and we can test things. When I signed up for it, I expected changes, new things to play around with, that’d put interesting mechanics. The MMO system is very basic, and has a lot of room for growth, and we wouldn’t have minded experimentation, and if something went wrong it could always be reverted. Right now the Early Access period seems to be a pathetic excuse for all problems the game suffers instead of a period for testing and refining the game’s system. Instead it’s been a constant deadlock.