These days we have much cheaper ways to handle uploading and downloading insane amounts of video content (if you're interested, I recommend checking out some System Design resources on TikTok or YouTube), but it's pretty much all CDN and slightly more efficient backend services). We also have better ways to monetize platforms. Like data. Buttt ByteDance is also trying to do things like set up physical goods stores/etc, and it's 2024 where userbase and brand name is more important than actual revenue anyways.
Twitter clearly mishandled it. All they needed to do was give the option to post longer videos. Classic example of a large company buying a small innovative service and destroying it for no reason. I assume they thought it was too similar and in competition with Twit's existing ability to post videos.
It wasn't about video length, it was about the Twitter leadership at that time being categorically incapable of monetizing any of their products.
Combine that with the orders-of-magnitude higher cost of running Vine compared to the bird, and it was always either going to be sold off or shut down.
It's easy to forget that this was back in the time when these companies thought they were changing the planet for the better and drinking their own Kool aid by the gallon.
The video length was pretty limiting, though. Instagram at the time started doing 15 second videos. The six seconds lent itself to goofy comedy and not much more.
It seems like they should have sold it. Or just jammed in a bunch of ads... maybe an option to remove ads with a paid membership. Simply killing it doesn't make any money other than to avoid losing more, and they'd already invested a fair bit which you can't recoup by just closing something. Of course, Google does that all the time I guess.