A very direct answer to any "Why not just fork X?" question is, would you want to develop and maintain the fork in your free time and for no pay? Forking any project is deeper than just copying a repo and then making a few changes.
This would involve finding a group of people intimately familiar with the codebase who also don't mind committing all of their free time to development.
When you fork a project, you also lose whatever payment/donation structure the original project had setup. Asking for some kind of payment to develop a larger project should not come as a surprise. You want to be able to attract halfway decent developers and they want their work to be valued. Beyond just approving PRs, you need a team to verify additions and work out all the conflicts and errors that arise.
There very well may be a lot of settings people all agree on. But who is going to bite the bullet and put in all the time to add those features, potentially for the fork to be abandoned?
I hope this doesn't sound condescending because it's not intended to be. I'm just trying to explain that the scope of "Just do this" is a lot larger than what it first seems.
Seconding this and wanted to add:
It's more or less the repo owner's job to keep the codebase organized. So if they created a set of standards, follow them. If not, submit as clean a PR as you can.