The solution in such cases can't reasonably be "everybody around the world learns to download one particular tool to fix things". In your example, the two reasonable solutions are either apple figures out how not to send image files to people that they can't understand, or the college board figures out how to convert heic into jpeg themselves. Otherwise, as in that case, most people will simply be left in a lurch.
The people with the know how to use such a tool are more likely to use a swiss army knife tool than a specialized one off tool. The article mentions someone using windows photo viewer to do the conversion.
The solution in such cases can't reasonably be "everybody around the world learns to download one particular tool to fix things". In your example, the two reasonable solutions are either apple figures out how not to send image files to people that they can't understand, or the college board figures out how to convert heic into jpeg themselves. Otherwise, as in that case, most people will simply be left in a lurch.