I cant stand the new i.reddit img service, but that could be me just being an off-my-lawn-er...
but I am wary of reddits motivations, as I dont trust the admins all that much given the fact that they are a huge social manipulation tool - and if you don't toe the corporate line in the US, they shut you down.
Other imaging hosts that serve up .mp4's as substitutes for .gif like giphy work just fine. It's just Imgur that couldn't figure out how to make this work properly.
It's effectively a tracking "pixel" for what you click, even if you block their javascript/redirect.
It also keeps that data in house which they can sell (if they need to) rather than give all that data away to imgur for free. Though I wonder if the bandwidth costs will break even.
They can also use it in order to craft personalised suggestions.
"Imgur was created as a response to the usability problems encountered in similar services. Designed to be a gift to the online community of Reddit, it took off almost instantly, jumping from a thousand hits per day to a million total page views in the first five months."