It's all intertwined. There are workers who are self-motivated, proactive and care about doing a good job, no matter what the job is (and often work a bit extra to make it all come together)... and there are workers who do what they are told and just enough to meet performance objectives without going above and beyond. Can you guess which ones will excel within a company? It helps the company, but it also boosts the individual's career, leading to higher responsibility roles and higher pay.
Ever since I was a kid, I haven't been capable of doing a half-assed job. Conscientiously NOT doing a good job would be more stressful than just putting in the work. If something is my responsibility, I do it to the best of my ability. From 5th grade homework to corporate presentations. That being said, as more things end up on your plate, it's important to understand which are truly important and prioritize. They aren't enough hours in the day to get everything done, but when my boss says "Hey, I need you to put together a presentation that I'll be showing to the VP", yeah, I put the time in to make sure it's good. If I make my boss look good, I will be rewarded with higher compensation down the road.