I haven't played genshin in about 3 year but i used to enjoy it, is it worth it to try it out again?

Dude only you can answer this question.

Well, you've got a lot of content to play. It depends on what you enjoyed about it and why you stopped playing.

But it's a free game, nothing stopping you from opening it up and seeing how you feel about it.

We dont know why you left so we can't be sure if your issues with the game have been dealt with or not.