yt-dlp works when ever I try it. I do not use it much but ever few weeks when I need to download a streamed youth ringette game, it works great. So while it may be in a constant race, it seems reliable to periodic end users like me.
It's getting much more difficult to run. YouTube often requires PO tokens [1] to download videos now.
Depends on the effort from the team. Very good testimony for yt-dlp's one.
yt-dlp works fine for low-volume requests from high-reputation IPs.
But if you try to download in significant volume, their systems know it's automated and probably have signatures specifically for yt-dlp.
I think it's a bit of an escape hatch: they know they can't close the hole (after all, there is always the "analogue hole", or now AI doing browser control); and probably prefer leaving a small monitored and rate-limited door than trying to patch everything.
See: Google changing their sponsored link DOM/CSS/classes matchers every (few weeks - few months) to break ad blocker lists, but they're certainly capable/smart enough to do it daily or hourly, etc.