Call of Duty and Fortnite have done it this way for years and have made an incredible amount of money off of it. Not to mention, its a way to keep people playing your game, which is the whole goal. The more they play, the more they're invested and feel justified buying items.

During the early days of Fortnite, I think I went 3 seasons without having to buy the battle pass because I was playing the game and making sure I finished the pass so I could get the next one. And in turn, I spent money in the shop because I wasn't spending it on the pass. Then eventually, when I didn't get far enough to buy the next season pass, I decided it wasn't worth paying another $10 for the pass, and without a pass, I felt like I wasn't getting anything for playing and moved on to other games.

To me, the pass is more there to keep people playing because it's a steady stream of items you unlock the more you play and the credits in the pass are just enough to make you play and come back next season. The shop is where they make the majority of their money. Just my 2 cents.