A good link provides your website with credibility. Google movies higher scores to links from reputable publishers. If you want to rank higher than your competitors, you’d need to acquire more backlinks than they do. And it’s a long-term effort.
The more backlinks you have, the more the web traffic to your site will increase in practice.
On the downside of things, if your site gets too many spammy links, Google will consider it untrustworthy and this will harm your ratings.