Is using Observer design pattern instead of Provider in flutter a good idea?

The thing is that i have an app where i need to manage data across widgets, and listen to modifications (like perform an action in widget "X" whenever the value of a variable in widget "Y" changes).

So i was thinking, instead of using a whole package and adding a library to my dependencies (i mean provider) and since dart is an Object-oriented programming language... i can use the observer design pattern (pub-sub). this way i can listen to variables' modifications and perform rebuilds only where needed!

Every interaction is highly appreciated!! THANK U!

btw this is my first question on stackoverflow xD