From Microsoft's perspective, they don't want players only playing Sea of Thieves. They are focused on Game Pass, keeping subscribers - and having players only play one ~4 year old game, with free updates, is not beneficial (they'd just buy that one game).
So the strategy for them is really to keep players engaged casually - coming back every big update, maybe spending a few Ancient Coins in the Emporium, and playing other games as well - where, again, they can sell them microtransactions. It's all aimed at keeping their renewal turned on and spending money in-game.
Rare are doing their best with this business strategy, whilst not seeming predatory - I'm sure it's a balance between keeping Microsoft happy and keeping players happy. It's unrealistic to think a studio of that size (200-300 employees) to be able to sustain a game like Sea of Thieves with massive updates constantly - when bigger companies (Eidos Montréal being about twice the size) fail to really nail the GAAS model.
Sea of Thieves is an amazing sandbox, but it is finite. If you play constantly and grind, then you will of course reach the limits of the content. I've been playing for almost 4 years, moderately. It's my main go-to game but I have only about 1,800 hours (plus a few hundred more in [REDACTED]). This is because I have a full-time job, commitments, and I like to play other games from time-to-time. I don't grind heavily and I'm never bored with the game, there is always sometime for me to do - to work towards.
It's come along way since launch, in terms of content and QoL, and I think we need to have that perspective rather than act like ravenous wolves, never satiated. There are many areas that I personally think Rare can do better (moderation, enforcement, Partner oversight and monitoring, more timely announcements) but there's no doubt in my mind that they've managed the game itself as best they can with what resources they have.
