Progress in games is not only when you get experience points, but you buy skills and characteristics with them. These are any new gameplay features and character changes https://epiccarry.com/wow/boost/vault-of-the-incarnates-mythic/ . Even if in the course of a linear game you are given a new weapon, this is also progress, just choreographed.

Progress has three main objectives. The first is to keep the player engaged—create a goal of sorts. Secondly, to make the gameplay more diverse - so that the player does not get tired of using the same. Thirdly, to set restrictions - so that it is impossible to immediately explore all the places or quickly “run through” the game.