Your character is at full power from day 1, so you only get stronger by learning to play better. The naval combat can take a bit of time to master but it's fun. The only thing you get for playing a long time are cosmetics. If you want to get sweaty with PvP then you can find a group on the SoT discord. Otherwise, for more casual play you can sail solo or join other players using the open crew matchmaking system. I have around 1700 hours in the game and it's just as fun as when I started.