I'm sure they have good marketing but that's far away from why I use it. At this point my whole life is in Notion. It's by far my endgame note taking app. The value is that it's so dynamic and infinitely nested and can absorb any messy unstructured thoughts or notes I have without having to stop and think about where it should go.

Like say I make myself a todo list using a List database. Need to set a reminder for myself about some part of it? Just add it in the list item with @. Have some documents or code output that you want to remember? Just throw it in there! Crap, have a billion tabs open from researching and have to stop for the day? Just create a list inside the page and throw all the links in there. Need to take notes on some of those links because the SO answer wasn't quite right, just add it right that list item. All the context for the card is right there in the card. It's a project management board that actually bings value to me as a dev. It's not the thing I have to use to track time, it's a thing I want to use because it's where I can store all my thoughts instead of having to have two systems and keep them in sync which is always a chore.