After playing the closed beta of skull and bones I am now 100% sure that SoT is a much better choice.

Sea of Thieves provides all the necessary tools to the players willing to dive together in great naval adventures, full of smaller quests and epic sea battles.

There is no nostalgia from this game like there is from Ezio or Altair, the last few games were well worth the money, with the dlcs, world, combat, and story. This is a four-hour-long game with poor combat because the "assassinations" are worse than in Valhalla, Odyssey, and Origins and most of the time, you are spotted, and then the regular sword/dagger cycle begins. Basim's story is terrible, and it appears that he lost his accent between games.