And by not everyone you can very well mean Youtube itself. I'm in Hungary, sometimes I watch gameplay videos that are only enjoyable in at least 720p and Youtube can't keep up with the bandwidth. I have a 1 gbit connection. And Youtube won't buffer the whole video if you pause it. youtube-dl is really a must in this situation.

I'm not familiar with the situation in hungary but isn't it more likely that your ISP is throttling or otherwise artificially limiting the connection to Youtube, Netflix and other services with bandwith-heavy content.

Well, they don't throttle torrent in any noticeable way (torrenting with 10-20 MB/s or even more is not uncommon). And torrenting is pretty active in Hungary. They also provide ipv6 addresses too, I really can't say anything bad about my ISP. But it could very well be them who do the throttling to Youtube, I can't any way verify that.

Try running it through a VPN. I recommend NordVPN these days. Had good luck with Torguard in the past as well.

But they don't download the ads, so I doubt they matter very much as far as google is concerned

FWIW, youtube-dl can download from a ton of sites...

https://rg3.github.io/youtube-dl/supportedsites.html

You can actually download the ads with YouTube-dl... I believe it's YouTube only and still named as 'experimental', but theoretically it could be a default to appease the big G.

But surely they arrive as separate files, and not interspersed in the main video. So it's implausible they'd ever be watched.

Yes they would most likely arrive as separate files. Though YouTube-dl could force their main codebase to merge the videos. Regardless from looking around it doesn’t look like ads are downloaded.

Do you know where to find this or if this is definitely true? I tried looking around before and YouTube-dl didn’t have any ad downloading ability. I just tried looking now and at first glance it doesn’t look like it does. Nothing in the changelog for past year either.

It can download ads. It is a command line option.

In my case a vast majority of use is just to be able to pipe the original stream to mpv/vlc in order to reduce the cpu usage. In the past there was a clear benefit, maybe less so these days.