I don't remember when was the first time I heard about it, but I used custom roms years ago and wasn't amazed from cyanogen mod back then.
Since I needed to replace my iPhone with a cheaper android phone I was looking how the situation was in regards of alternative roms or maybe Linux mobile etc.
So I gave GrapheneOS a try because there was no AI and it left you with the choice to use it completely without Google or to use it like a Google Phone, but with better security and without constant surveillance. Also that you could fully install it via a browser without flashing some tools beforehand and it can be reverted on the same way is great.
I am happy with it so far and plan to use it for several years, it seems very stable and everything I really need works so to say out of the box.
I like it better than Stock Google, though I admit that most people will want the AI stuff and things like Google Wallet Payments, so I understand that probably only a few will make the switch.
But it is worth it, though it behaves like a normal Google phone, it feels different to know that only the minimum amount of data is used. Being under no or almost no surveillance from Google is a good feeling.