system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why don't more websites host their downloads via torrents?

I don't see a drawback to it. 

You wouldn't have to pay for a server to host your file. 

Higher download speeds for your clients.

More availability with 200 seeders compared to hosting it on one single server that could be down for a day. 

Ubuntu hosts their image file via torrent. Why haven't other people followed in their steps?
gpt
Torrenting requires people to already have a properly configured client. For a lot of people that's an intimidating requirement, and the current Internet culture is (understandably) such that most people would rather accommodate ignorance than try to correct it. For downloading a Linux distribution, if you've already decided to run Linux, you're probably able to learn how to torrent to do so.

Though it's worth noting that the download clients for some major software, like World of Warcraft, actually uses peer-to-peer transfers as well. It's just without any interaction from the user.