Why can't most people open a server on DigitalOcean or Vultr where the price is $0.01 per GB? 117 Subscribers, for $300 per month, it's almost possible to start a VM per customer.
I'm not sure which CDN. I looked at AWS EC2 and Fastly and they both cited outgoing bandwidth that was twice as high. Given that I can't find hosting providers with lower bandwidth costs, DO/Vultr either have very specific peering agreements or are subsidizing their bandwidth charges; either of which would be utterly broken by the amount of bandwidth that the person from the article appears to need for their multi-hour art tutorials.
Even if they had an amazing deal on transit, or were peered with everyone[0], and were able to provide $0.01/GB to video hosting at scale, we're still talking 20-40GB/view (assuming 45Mbps delivery of multi-hour video content). Delivering that over 800 views will run about $320 per video. Vimeo's cited custom plan pricing in the article is basically assuming a video per month on average at those rates.
[0] This is the particular reason why Google is able to provide YouTube at all. They are so big that every ISP absolutely has to peer with them, and that drives down their costs significantly.
it's probably using less than 10% of CPU or bandwidth most of the time
multiply it by 1000x and you can imagine how much leftover bandwidth there's left for the heavier users (beside they're not selling unlimited, you have a generous tier included and you pay extra for overages)
There's plenty of providers that can match the pricing
I've also worked for a company heavily relying on vultr and they have no problems handing high volume bandwidth (they're not as cheap as Hetzner!)
You'd also have to re-implement access controls and probably integrate a not-terrible video player. There might be open source software that does that, but nothing springs to my mind.
I've got the skills to do it, and $300/month seems high, but not unreasonable. That $300 a month frees me from doing updates, having to wake up at 3am because the site is down, having to transcode my own videos for lower-bandwidth clients, etc. It's probably roughly on par with paying someone else to do all of that stuff.
Works well enough for me as a slingbox alternative but I'm also not running it as a business.
[1]: https://hls-js.netlify.app/demo/ [2]: https://github.com/aler9/rtsp-simple-server