I downvoted you because your comment is difficult to follow. My best interpretation is that you dislike iOS Safari because it doesn't support a specific CSS feature (one that makes little sense on a touch device), but you don't care enough about iOS to find a workaround. However, you do care about IE8 (a browser that was released 7 years ago) enough for it to be a non-starter to ignore it as well.
That's an interesting business decision, but to each their own. Regardless, none of your comment seems relevant to the ongoing discussion of replacing gif with webm and the difficulty of finding a universal format.