TLDR: player choice is how you make a good season

The biggest win in my book for this season is very simple. They offered players a choice over and over again.

You can choose to farm nightmare dungeons to level your glyphs or you can take a break from that to do tree of whispers which allows you to fight Varsh. That feeling of having to decide how to spend your time is so important.

You are in a helltide... You can choose to spend your cinders on loot now with a mystery chest or open the living steel chest to get loot later and get materials for Duriel. Early leveling you might choose immediate rewards but then you choose when living steel becomes more valuable to you.

You also have blood harvests which even at high level stay relevant because of the very fast tree of whispers gain.