There are lots of useful changes you can make that don't break the world but do materially improve things. I already gave an example elsewhere of aws-vault. Similarly, CI/CD/code review are easy wins that not everyone has already. You're assuming everything is copacetic right now, but that's not a given. I doubt any startup would take the position that there's nothing left to improve. That doesn't mean you're going to start by burning the world down and starting over.