Buttons are a more important part of website design than ever, as the increase of mobile device usage continues. Buttons give the user a clear indication that there’s something they can do here, and they’ve been proven to increase interaction rate compared to links in most circumstances. They’re also one of those things which can be updated on a website without going to much effort, and certainly without waiting for the next website redesign.
If your call-to-action is, for example, a link saying “click here to download the data sheet”, or just an icon saying “PDF”, have you thought about replacing it with a button?
There are quite a few considerations in button design, and I’d recommend reading A Quick Guide For Designing Better Buttons by Nick Babich in Smashing magazine for the latest thinking.