Mine is that the useState hook is an actual plague on the entire React ecosystem. Regardless of your opinions of React, if you wanna use something then use it right.
OOP dogma isn't just bad, it's actively harmful. OOP leads to unnecessary boilerplate. Any boilerplate that is not absolutely necessary is noise and bad. Full stop.
Private (Getters/setters): Strictly not a necessity in any sense of the word.
Short functions everywhere.
Short files everywhere.
I prefer to see the steps of execution that are actually happening in the real world on hardware. Not an ivory tower of code that happens to execute.