Look into “how a company works”, because that directly works against anything you say.
Not that I disagree with your ambition, I would like to only ship tested code. But if you’re working with deadlines and fixed budgets, that’s often enough impossible. I can’t even get a proper specification out of my clients, and even if they do, it’ll change in a week. You can be as agile as you want, if money runs out, there’s not much you can do.