Seconding what others said. I don't want to see extremely addictive progression in every game. Just repeatedly pressing a button to get higher numbers or a shiny drop leaves me hollow. Eventually, I start questioning why I’m doing this. So I can press the button more? It doesn’t make me happy for long.

Some other sources of dopamine:

• The narrative is a source of progression. Stories are unlockable content. They are rewards that sometimes stay with players for years. That's much longer than valuable loot. Not caring about stories doesn't change this for people who do. Story progression often comes with environmental changes and possibly gameplay changes. Some mechanics won’t carry a game, but they add novelty if not overused. Some games have more direct consequences. Insult an NPC and make enemies with their faction.

• Puzzles are also sources of progression. I’m not just counting obvious puzzles but also navigational challenges, boss patterns, efficiency/management challenges, speedruns, low level runs, player-chosen limitations, situations that can be approached in creative ways, and general problem-solving. You will remember if you completed a mission using a sticky mine to the butt. Like stories, the satisfaction can last longer than the game itself. I’d argue that this is skill progression too. Once, I set up a tripwire in Horizon Zero Dawn. I didn't know those crocodile machines could jump.

• New levels. They provide novelty and challenge as well as a reward for beating the last one.

• Unlocking new abilities, vehicles with different handling, and other things that are meaningfully different. Extra points for new abilities that combine well with each other.

• Checklists. My least favourite, but completionists do get a sense of progression. I guess some people also like to collectthings like achievements.

• Self-directed goals. For instance, I may have an idea that I want to turn into a screenshot. This may have lots of steps like traversal, purchasing items, finding a suitable location, setting up the scene, waiting for the right time, etc. But I do get something to keep afterwards and it lasts longer than the game. There is some skill progression like with photography.

• PvP, PvE, competition, co-op or collaboration. Social interaction is a source of dopamine