At its simplest; the economics of hosting video quickly become unsustainable.
A well formatted blog takes maybe 1MB at most per request (a really well made blog can lower that quicker). 20 minutes of 1080p video is ~500mb according to most YouTube downloading tools. Hetzner offers you 20TB of free internet traffic per month for every VPS you buy.
That one blog can be send up to 20000000 (that's 20 million!) times to people every month before you'd have to start looking for CDNs or other fancy solutions. By contrast, that 20 minute video runs out of bandwidth after 40000 (40 thousand) times before you hit the same scenario. (These are hypotheticals, of course you'd incur more due to traffic overhead and the realistic answer that you'll have more than one page/file on your site.)
It's essentially a scale problem; bandwidth is really expensive if you don't outright own (and have the need to use) a data center or colocate. (And even then it's still expensive, it just goes from completely unreasonable to "maybe a sustainable business".) Alternatively, CDN solutions also get very expensive very quickly at the amount of traffic that digital video tends to consume (which wouldn't be selfhosting it anymore, but is worth a mention).
And that's without going into the discovery issues or the fact that browsers accept much fewer codecs than you'd expect for video playback (which can further bloat up storage size as you might have to use less efficient solutions.)
A well formatted blog takes maybe 1MB at most per request (a really well made blog can lower that quicker). 20 minutes of 1080p video is ~500mb according to most YouTube downloading tools. Hetzner offers you 20TB of free internet traffic per month for every VPS you buy.
That one blog can be send up to 20000000 (that's 20 million!) times to people every month before you'd have to start looking for CDNs or other fancy solutions. By contrast, that 20 minute video runs out of bandwidth after 40000 (40 thousand) times before you hit the same scenario. (These are hypotheticals, of course you'd incur more due to traffic overhead and the realistic answer that you'll have more than one page/file on your site.)
It's essentially a scale problem; bandwidth is really expensive if you don't outright own (and have the need to use) a data center or colocate. (And even then it's still expensive, it just goes from completely unreasonable to "maybe a sustainable business".) Alternatively, CDN solutions also get very expensive very quickly at the amount of traffic that digital video tends to consume (which wouldn't be selfhosting it anymore, but is worth a mention).
And that's without going into the discovery issues or the fact that browsers accept much fewer codecs than you'd expect for video playback (which can further bloat up storage size as you might have to use less efficient solutions.)