Communication is 80% or more of working at a software company.
The point about preserving relationships is important. I think there is a common idea out there that a lone hero engineer is gonna single handedly make the company work. In reality, most of us are just average cogs. We need to get along and work together to do great things.
When I was on a drama filled team, PRs took longer to review, meetings were long and stressful, designs were crap because it was all about getting your way. Productively was in the dump.