In solidarity with the blind and vision-impaired community, I propose that twice a year, on the World Sight Day and the Global Accessibility Awareness Day, fediverse admins disable images on their servers to highlight the importance of writing good image descriptions.
Well, convincing admins of big instances to get onboard with the idea is an uphill battle, as you'd expect.
So maybe something like regular folks posting descriptions of the images they'd normally upload instead of the images themselves could be a good, arguably less impactful alternative?