Good dev: test suites, documentation, tracking

results: decent coverage, more predictable, more maintainable, saves time and money, accountable to stakeholders, happier team thanks to transparency

environment: matured middle-sized to bigger company who takes things seriously (because they usually have to if they work in a heavily regulated sector)

Bad dev: idgaf attitude, let's just run with it and see what happens flow, go for bare minimum happy path

results: a new bug at every possible situation, mystery bugs, an endlessly-growing backlog where people in the team are so depressed no one cares what ticket to take on, morale goes down crapshoot and so does code

environment: start-ups who want quick wins and make money-based decisions only and whose budget is being guarded by the higher-ups

I've worked with a bad dev before and also with a good dev and I appreciate the difference. lol. Nightmare.