This was my experience as well. Early on, when I was still learning, it helped me learn the importance of extremely low Time-To-First-Paint. But now, I just default to good designs that are easy to read. There's nothing new to be learned that GA could provide insight on.

Also, early on, I found the Referrer tracking to be useful for discovering the reach of my projects and to help me get into conversations with users on other sites to help them with using my software. But that feature of GA eventually became useless when Google did nothing to address Referrer spam.