Currently, images and files can only be uploaded to the contact record using a form, and that creates limited functionality because those files only live for 10 minutes once shared, whether they're shared in an email or on a web page.
Uploading them directly to the Media Library allows us to populate websites, for one, via form upload rather than having to go through multiple steps of uploading, renaming, and then going into the Funnel Builder and selecting the proper image. And for most of us, that's not a big deal, although it would save us time as well. But when having users update their own images on their websites, it becomes problematic. And a form upload directly to the Media Library can solve that problem.
As well as many others, like the fact that the images or files once shared can live for more than 10 minutes. Because if someone doesn't check their email within 10 minutes, it expires. Or if you post an image on a funnel or website, it's going to expire. Rendering all of your work useless.
This would then allow us to do many creative things using custom fields, custom values, mapping, workflows. We can literally update pages with nothing more than a form submission. That would be absolutely game-changing for many users.