Every time I try to download something, I just get an ad to upgrade to the Pro version.

Potrzeba zapłacić by działało.

have to pay

Downloading 1080p requires "pro" version, because addon cannot simply connect steams with ffmpeg

HD and better Q only for PRO users

Фигня! При попытке скачать видео предлагает купить ПРО версию!

It doesn't work: "Youtube switched to separate audio/video streaming technology for higher quality formats and no longer provides direct 720p (Since 24 September 2018)/1080p/mp3 streams. Converting these streams to downloadable formats for you needs powerful server infrastructure, therefore 1080p/mp3 downloading has been limited to PRO users. Read more at - https://videodroid.org/pro_upgrade.html. FREE users can download all formats in CACHE where some PRO users fetched the video/audio in past 24 hours, to test the feature you can try downloading popular videos."

Не работает.

not working

Added the add-on. Went to Youtube. Tried to pull a single mp3 and the first message I get is "Converting these streams to downloadable formats for you needs powerful server infrastructure, therefore 1080p/mp3 downloading has been limited to PRO users." FAIL. Removed.

It doesn't work.

basically a demo

What they don't tell you is that You have to be a "pro" user in order to download mp3 and 1080 hd videos. In that case I'll rather get youtube premium.

Used to be best free Youtube content downloader. Now it's not free

charges to download HD files, but other extensions (e.g. Youtube Download Full HD) do not.
or you can use websites as https://y2mate.com .