Boilerplate is only boilerplate if it's the same everywhere, which it shouldn't be.

The trouble with leaving the verb off is that if a user experiencing low or no vision is browsing with the aid of a screen reader, they may not be able to determine what the noun is for. Screen readers can scrape the current page and create lists by content type (headings, links, buttons, etc.) for easer navigation. Static text that is placed in visual proximity to the download links will not come along for the ride if accessed via this method. While it might seem redundant to show the word “download” over and over again, including it can go a long way to providing context for users navigating without visual aids, or who have zoomed the page’s content to the point where the layout may not communicate the visual relationship.

One lesser-appreciated user-behaviour is when a user would like to choose an alternative download location. On a download link, your user can right-click -> “save link as…” and place the download directly into a folder of their choice. Handy if you want something to go directly to removable media, for example. On a download button, there’s no such option.