In that weird era, (a) average home Internet connections became fast enough to support streaming video (with a healthy adoption growth rate), (b) the most widely deployed home recording device was likely still the VCR (digitizing analog video from cable to burn to DVD was a pain), (c) there was no "on demand" anything, as most media flowed over centrally-programmed cable or broadcast subscriptions, and (d) people capturing video on mobile devices was rare (first gen iPhone couldn't) but obviously a future growth area.
So early YouTube was literally unlike anything that came before -- watch a thing you want, whenever you want.
Really most of the content that YouTube had available was material recorded off of broadcast/cable which was mostly not available otherwise unless you had recorded it or gotten it off a torrent.
I remember uploading it from my Sony handcam, then editing it in Sony Vegas and exporting it to make sure it hits the required YT file upload limit.
I'd be fascinated to look at their peering terms.
I honestly don’t think YouTube would exist without that particular piece of regulatory capture.
Contrast the video and podcast ecosystems.
Podcasts are arguably much healthier (the publishers maintain creative control), and are certainly decentralized.
The Techmeme page from the day of the announcement (October 9, 2006) if you want to dig into it: https://www.techmeme.com/061009/h2355
Lots of people carried digital cameras, but even more have mobile phones.
Sadly, the copyright cartel swiftly attacked and all the regular people lost their rights. It seems like the lesson learned is that the copyright-owning corporations can't be trusted to play fairly or meet in the middle on fair use. We really need to just abolish copyright laws entirely.