A strong work ethic is crucial if we want to make more of ourselves and seek self improvement. If we find ourselves working in a job we don't like, we must be ready to make a tough decision. We must either decide to grin our teeth and bear it, or we have to be ready to move to a job we'll find more fulfilling. These are the only two choices that really matter if self respect matters to us at all.
Even if you dislike the work you do, a good work ethic that shows we are eager and willing will almost certainly get noticed by the people who can help us advance. It's easy, like many do, to take the low road and do the minimum amount of work possible to get by, but this is never going to lead to promotion or advancement. However this is only a valid approach for those who have no interest in self improvement and building a better life for ourselves.
It's an oddity then that plenty of people pride themselves on doing as little as possible, seemingly beating the system or pulling the wool over the eyes of their employers. This often however leads to yet more disappointment for those people; they complain about their jobs not being fulfilling enough, often because they don't work to find the fulfillment that there may be in working hard. And they are probably the most vitriolic people you're likely to work with, as they find their amusement in office politicking and rumours for the same reason they complain about their work; a lack of a strong work ethic.
On the other side of the fence, there are those who work hard and work well but seemingly get ignored by their managers and employers. They find themselves perhaps doing more than their lot in an effort to get noticed, and are often willing to take on tasks that would otherwise not get done to show that they are motivated and hard working. In these cases moving on is often the only reasonable choice available, so that they can try to find a job - and an employer - that will value them to a fair degree.
Making sure we are up to date with all the latest goings on in our working field, as well learning new skills that could further our abilities in work, is very important if we want to advance in our career. Keeping motivated will also help. If your goal is to advance up the corporate ladder, or start our own business, have a strong and pronounced work ethic is perhaps the most vital thing needed for success.