I disagree in some cases. Code is a means of communication. Sometimes it's more efficient to write code and bring it to your team than to discuss it in the abstract.

An example of this might be adding load shedding. You could spend hours talking through it, or you could say "I'm going to add a load shedder to the blah service as a proof of concept" in standup then take an hour to implement it, and have the team critique it from there.

I agree that whether they're a useful gate is debateble, but they can be a useful means of expressing an idea to be approved or rejected.