Marvel doesn't do a lot of PG-rated projects. And even those that did get the TV-PG rating (no films in here because you know it), most failed to keep the rating.

Here's a list of MCU projects that had the TV-PG rating:

* Agents of SHIELD (later seasons were rated TV-14)
* [WandaVision and Ms. Marvel (later episodes were rated TV-14)](https://www.reddit.com/r/MarvelStudiosSpoilers/comments/v5g6z9/ms_marvel_is_now_rated_tv14_instead_of_pg/)
* I Am Groot
* Your Friendly Neighborhood Spider-Man (?)

Technically, it's still possible that Your Friendly Neighborhood Spider-Man loses the TV-PG rating by breaking Gwen Stacy's neck in future seasons but I'm not sure, she's Ghost-Spider.

So I am Groot is the only MCU project to be rated TV-PG and to keep that rating.
Fun fact: I am Groot is the only MCU project to keep the PG rating from start to end.