I've tried invidious and pipepipe/newpipe.
E.g. can't watch this rather innocuous short abt fireworks affecting animals
https://invidious.nerdvpn.de/watch?v=3qbR8TqdBjc

Send it to your neighbor and climb up that tree with the sturdy branch by their window.

If you mean directly, yes, IFAIK. At one point youtube-dl could download them.

Someone could probably set up a proxy tied to a bogus account, but I expect that YouTube will block them if it picks up on it.

Try a different instance and/or swap your VPN if you have one. If not, get a VPN service regardless whether IP is the root problem or not.

I searched the title of the video & the same title is on Instagram. I was then able to download it via YTDLnis (GitHub, although I installed my copy via F-Droid) on Android.

I have attempted to watch a “Hey Ash, watcha playin?” video without signing in and have been unsuccessful. Tried a few different systems with no luck. Yt-dlp could not grab it either. Alternate “tricks” seem too risky.

You might be able to watch it on Linux using Freetube. Never tried it though.

Yeah, for some time now, youtube-dl requires the login cookies being exported from the (logged-in) browser to be able to download restricted videos.

And setting up a proxy will probably not work. They do rate-limiting. Seems they also know which IP addresses belong to residential internet connections and which to datacenters and VPNs and they'll cut off the servers. And with Google you always risk your account being flagged for "suspicious activity". I had that happen to me as well (unrelated to YouTube, though).

Yeah this is bothering me lately too. I mostly use PipePipe on my phone, but have been hitting this barrier. Sucks for us I guess.

Yeah, I'm saying that this was just in the past --- they closed that hole years back.