This is sort of just part of the game as a service kind of environment that SoT has. As was noted, the same is true about a lot of events. Hungering Deep, Cursed Sails, and so on. So this isn't actually something new with Adventures even really (the new part is that there is potential for more drastic changes to the game world itself, like potentially destroying an Outpost).
Additionally, this brand is going the direction of a multimedia one and as such a lot of the SoT story takes place outside of the game and always has. There are novels, comics, etc. They all feed into the narrative of the game world and are part of the storyline. This is similar in respect to something like Star Wars, where they have the movies of course. But also books, comics, Disney+ shows, and so on.
This allows for a unique kind of storytelling that is, personally, a refreshing thing to see. The game and the story of it will continue to change and evolve over time - you'll experience some of those moments and you can cherish those that you participate in as part of your personal journey with it. If you crave more beyond the gameplay time you can invest then you have options available to you to expand upon that (read the books and comics, check the website, watch videos, etc).
Just like in life, it is best to focus on your own experience and take what you can from that as opposed to stressing over the experience of someone else or getting hung up on moments you didn't get to be a part of yourself. It is different than an isolated experience where you know all of the content will be there for you whenever you decide to jump in because the experience will remain static. That is of course a valid form of videogame and storytelling, one where many examples exist out there already with more on the way all the time. This is different, and it is up to you if that is an experience you are willing to embrace and cherish for what it is or not.
Accommodating something like this would actually be a pretty massive undertaking from both a development and a logistic standpoint in an attempt to "appease everyone" which is a fools errand because you will never hit the mark for every person and set of desires out there. As for me, I absolutely love the experience that SoT brings to the table. It is why, this many years on from launch, I am still playing this game and haven't fully moved on from it. It is something different and refreshing in the space that hits the right chords for me. I would assume that I'm not alone in this line of thinking either.
So, take breaks when you need them, but don't beat yourself up over having missing out on moments. There will be new moments around the corner that you can be part of yourself.
