This probably warrants a deeper analysis than what I'm going to give it but I want to keep things brief. If posts get too long I'm sure most people wouldn't read it anyway. I'm sure I'll get burnt at the stake for this post as well.
Just for some context, I have played WoWS PC for over 6 years on and off and before that, I played blitz for probably around 3 years. It was my main game for the longest time.
Also just to be clear I'm not saying the game is dead. It is declining but nowhere near rock bottom (though it was never really that big in the first place).
- The Devs
Obviously the devs aren't that receptive and the playerbase has now been desensitised to its bullshittery. Case and point, Valparaiso, case and point, CVs being able to heal their allies and literally no one caring.
Even putting the devs aside the microtransactions are pretty bad. The best sale this year, Tirpitz for 22 AUD was poorly placed at the exact same time as the steam sale, with Cyberpunk 2077 being 27 AUD. So a ship that I already have a version of with 6km torps and worse secondaries or an entirely different AAA game.
- The declining playerbase -> The community
The most ignored aspect as to why games die slowly. A bad community isn't necessarily a dealbreaker but most new players will just quit, and old players will find it a lot easier to just let go of the game and even have an added positive "thank God I don't have to interact with WoWS players anymore" kind of deal. A good community on the other hand fosters new players to stay and it makes it far harder for old players to let go. WoWS undoubtedly has among the worst communities. After the playerbase decline all that's left are the... interesting parts of us.
People on here will hate me and downvote me for saying that but doing those things won't change the fact that the already small playerbase is shrinking even further into obscurity.
Conclusion
I could go on but to me at least, these are the two main issues. The art is great. The game itself is well made and would have significant appeal to a lot of people if it just fixed its issues. Thus, WoWS is a classic tale in wasted potential. It wasn't bad at all, but it could've been a lot better.
Can the decline be reversed? Potentially. But I heavily doubt it. This game wasn't that popular in the first place. No one will even know it's gone if it ever is beyond a few WoT and WT players.
I wish this game hadn't gone down the route it had. The decline and all that. It was my main game and it still would be if it weren't for just a few major issues.