When I was a teen a couple decades ago, I taught myself Java from a book I bought at a library. I forget the name of the book and the author, but the last chapter included advise on how to program in a team. And the advise went like this: never give negative feedback unless there is a very important reason to do so. Appreciating others' styles and choices reinforces a positive culture and makes everyone in the team happy. This is more important than what background color has been chosen for a UI, or what design pattern has been used for some code. I have followed this rule all through my life. This might make me a non-challenger, but I know from experience that feeling good about the people you work with is what produces the best results

*I actually am a very annoying reviewer, but it always is due to code tidiness (comments, indentation, simplicity, etc), rather than my personal view on what pattern or design needs to be implemented