This becomes more and more important as the team grows, as there are more feet that you can step on. Working on a large team is really different than a solo or small team. Large teams are as much about communication, mutual respect, and shared goals than writing good code. Unfortunately, communication takes time and energy, and necessarily slows down the entire process, but it's critical.
The Mythical Man Month lays this out nicely. The possible lines of communication in a N person team grows quadratically at N*(N-1), which explains why large teams are often far less efficient on a per-person basis than smaller ones.
The microservice approach has its own problems but hints toward a direction where teams are small and autonomous, with ground-up freedom on the architecture of their little service and free from draconian oversight. I'm not an advocate of microservices, but it's an approach that hints at something different.
in a professional context requiring collaboration, that's an asshole move, and people who do that sort of thing on a regular basis should be reprimanded.
Being free to do things your own way often means choosing not to do something if it's going to negatively impact other people. Once you realise that you need to think about the way your decisions impact other people you quickly realise that compromising on your choices for the benefit of the wider team results in much better code.