There's an aspect to "the uploading problem" you didn't name, which is the "uploading services rapidly turn into hosts for pirate and illegal content, and even if that doesn't bother me ethically it bothers me when I get the bills" problem. "Storing on S3 infinitely" only scales as far as your pocketbook.

(Also, by "illegal content", think "Feds literally busting down your door and hauling you away" sort of illegal content, and by "you", I mean, you, va1en0k. This is not necessarily a reason to stop right now, but don't get too far down this path without legal consultation about how you should protect yourself from this eventuality. There are things you can and should do, like make sure you qualify for DMCA safe harbor provisions.)