The truth is that Adventure made people overestimate their ability, Arena too was populate mostly by averages.
In other games, League of Legends for example, competitive players can go for a dedicated queue and climb the ladders, the more you climb the stronger the opponents. It's a slow journey where you learn everyday and get better because you keep fighting players about your same skill level, the opponents' skill level raise directly proportional to your skill. You improve because the level of challenge constantly raise and so you need to adapt if you don't want to get demoted.
The lack of a ranked mode in SoT makes people think they're much stronger. The lack of a skill based matchmaking in Adventure and Arena means that a player that puts some effort in the game is being matched with casual players that just want to have fun and have no real interest in getting better. You basically win 70%+ of the fights just because 70% of your encounters are against people who are not trying as hard as you, truly tough fights against VERY GOOD crews in Adventure are VERY rare.
I personally enjoyed the PvP aspect from the start, I'm not a good FPS player but I used to win most fights even of my first month of playing, me and my friend used to do Forts all night and win most of them on our first month.
Playing against average players who are not decent in PvP most of the time and only rarely finding a very good crew just makes players who are just decent (and not GOOD) not feel the need to improve, they'll get mad when losing to a good crew, they'll have some tough fights, but being against bad players all the time just doesn't give a decent player the need to improve, winning that much also makes people more arrogant, decent players think they are much better just cause they win a lot, they don't realise they win simply because they were matched with bad players.
Having a lot of hours in the game tells nothing about your skill, if you think otherwise I could try explaining to you why it's not but other than that I would see no point in talking with you as that would mean you don't understand how improving and learning works.
Being a day 1 player tells nothing about skill, even less than hours played.
Being a long time insider has nothing to do with skill nor PvP.
Being a PvP based player tells nothing about your skill, just that you enjoy it. I've been a PvP focused player since my first week.
Not even Legendary Sea Dog means anything, when I decided to get good at PvP I started playing it with a friend everyday, on the first week of playing we already started getting 10 games winstreaks, we got the commendation in less than a month by winning 95%+ games. In order to get Legendary Sea Dog and Triumphant Sea Dog you just had to be decent, not good, it just takes an amount of time that is indirectly proportional to your skill.
Your gameplay is the only product of your skill and knowledge, you can't use random statistics like hours played or random achievements like "Legendary Sea Dog" as proof of your skill. While I understand why you would do that, I did it myself sometimes, we have no tools here to demonstrate our skill so we try to use stuff like hours played or Legendary Sea Dog, but at the end of the day the truth is these things means little to nothing.
The truth is that the lack of skilled based matchmaking inebriated players like you, making you guys thing you are the top of the food chain just cause you win most fights without taking in consideration the skill of your opponents. Now that skill based matchmaking is here and you finally regularly play against people of your skill, or even better, you get frustrated cause you were not used to lose so much, you get frustrated because you are used to fight against people that are bad at PvP, that do not know how to react to the strategies you settled on instead of improving, you complain about your opponents cause venting is easier than accepting that being at the top of the food chain was just an illusion you inebriated yourself with.
I don't mean this as an insult, I don't want to sound elitist. It's just a phenomenon that I've observed in SoT over the years and Season 8 proved it, it's also about a lesson I've learnt myself years ago. League of Legends is the first game I played competitively, the first time I got around Gold 1/Platinum 5 I started getting arrogant because I was better than most players, the first big lesson I learnt was that the Difference between me (a Platinum 5) and a Diamond player was even larger than that between me and a Bronze Player, I learnt that being in the top 30% =/= being good, I just accepted I was bad at the game, I was just putting in more effort than other players into learning the game and playing. As soon as you accept that you're actually bad an almost infinite room for improvement opens up before you, only then I unstucked myself from a skill plateau and was able to get to Diamond 1 in basically 2 Years (which was top 0.0x% at the time I got there).
I think it's as important to getting better in the a game as it is for everyday life to realise about our arrogance and how it affects how we perceive ourselves.