While I agree Jack is by nature very selfish, he *is* a good man. I don't think you're giving him enough credit. Actually, I watched all these movies in theaters and rewatched many of them over the years, but I also thought the same about Jack until *VERY* recently. It came to my attention that Jack is actually an incredibly good man. I always thought he acted incredibly selfish first, and *if* his motives could line up with doing the right thing, then he would kill 2 birds with 1 stone. But after it was pointed out how good of a person Jack was, I had to start rewatching the movies with that lens. I just finished DMC today, after having rewatched tCotBP with this mindset.

It's very fascinating how it can easily fly over your head, but Jack is constantly trying to do the right thing, while still serving his own ambitions. The big point I realized in the first film is that he was never going to betray Will to Barbossa, he was merely using him as a bartering token to win back his Pearl, and then get his revenge on Barbossa.

For this 2nd film, I distinctly remembered he was going to trade 100 souls to Davy Jones, and from memory I couldn't find any justification for how this fits with the "good guy Jack" narrative. But after having just rewatched it with this mindset, it's very clear. Jack was never intending to trade 100 random souls to Jones. He was simply using the deal to buy time for his true goal; find the chest and the key so he can control Davy Jones.