POE is my most played game by far, and for anyone that hasn't really played POE before in any real way and wanted a way to help understand the draw beyond just the minute by minute gameplay, I think I can help to boil it down.
So ignore the gameplay for a moment and let's pretend that all ARPGs look and play the same (they are not the same but pretend)
POE is the game with one of the highest quotients of permanent incremental forward progress. The way that items and currency are acquired, and the fact that currency in POE isn't just gold count go up, and the currency drops themselves have direct and tangible gameplay implications means that every time you play, no matter how long, your character and future characters are taking these continual steps forward, and depending on your luck, sometimes great leaps forward, means that even though the game is ridiculously deep and wide even if you just dip your toes in the water it still works.
You don't need to follow anything to be successful, and you don't need to play a certain way to have a good time. All of the 500 systems are just 499 more systems than most other games in the genre have, so worst case scenario you can ignore most of that extra content and have the same or similar experience to any other ARPG game. The very top aspirational content in POE is Everest, and you don't need to have climbed Everest to have climbed a mountain.
There is no game I am more excited for than POE2 for myself personally, but for other new players as well. What I have seen of the streamlining of features is just what was needed for new players, but at no point seeing any of the new content reveals have I thought the game was dumbed down, they really seems to have nailed that mix between the two player groups.