Who requested this change? What is the scope? Where is the upfront documentation?
Now imagine the PR is ready to be merged. Since the engineer doesnt like documentation (as you are suggesting) then theres little context into what this is doing, who it will affect, and what types of changes can be expected.
Now imagine those PRs create a bug and causes an outage. Where do you look to determine the context into why this decision was made?
Now imagine a dozen of these teams working on the same repo. How do you coordinate who is working on what and what types of releases need to be schedueled?