You might consider making the language in your alt text actionable, such as "Click here to download the ultimate content creation kit." Actionable alt text will essentially turn every linked image into another CTA. So, even if someone doesn't see the snazzy GIF of my latest offer (or if they hover their mouse over an image that does show up), the alt text will beckon them to click.
This article is by far one of the most interesting and fun articles that I have read in a long time. I say fun because the points mentioned here are simple and easy to read. They are not long passages that speak a lot and tends to lose focus. On the contrary the points mentioned here were in short crisp sentences that did not bore me but made my read a pleasurable one. Thanks!