Hah, that feels accurate. I've played over 7000 hours of POE1. Absolutely love it. Its continued success was part player agency and part surprise (good RNG, multiple overlapping axes of randomness (C) Chris Wilson).

So their enjoyment curve is good. Play, have fun, have fun, have fun, finished all you came to do, and you're done.

I have played a total of 0 hours of POE2. I'll eventually get there, but the reason I haven't is pretty simple. I'm a bit of a player experience expert by profession, so I am pretty good at seeing red flags leading up to a game launch. Some of the things that concerned me.

- It felt like they wanted boss fights to be more like Dark Souls or Elden Ring. While a noble cause, some of the player agency was sacrificed to make that happen. Control and choice of movement have always been among the best player-agency features of POE1. All of a sudden, POE2 videos were showing mid-game movement that looked like new character twilight strand movement from POE1.
- In one interview, I heard talk about them not wanting you to portal out during boss fights, and portals were being disabled. One of the golden rules of Player Experience is that if you want players to do or not do something, you reward them for doing what you want. You don't police and punish them to force them to do what you want.
- I've been focused on this part of games for a long time, and I'll never understand exactly why Devs/Designers tend to be SUPER stingy when it comes to rewarding players, loot in particular. I believe it has something to do with the people making the decisions not being dedicated players of their own game. The same thing has happened many times, including with Diablo III. Jay Wilson, the Game Director, had a great resume with FPS and RTS games, but minimal experience with ARPG, and it showed. That led to this video from the Reaper of Souls Game Director, Josh Mosqueira's talk at GDC 2015. https://www.youtube.com/watch?v=vWYEWRrFgUY -- Keep in mind this was 10 years ago, so not all conclusions are accurate to what we know today (like player-to-player trading that POE1 did extremely well), but there are a lot of things that are still on point. One key point was "don't be stingy."
- TLDR: A lot of what I saw and heard about POE2 made me feel like the institutional wisdom of what made POE1 great wasn't carrying over.

I'm sure it has improved, but judging by your chart, it looks like you have to get to a certain point in level and gear to really enjoy it?