JDownloader 2 is a powerful, free, and open source download manager. It is designed to fetch anything that a URL points to to the extent that this is possible.

It can serve as a free alternative to dedicated video download programs, and like such applications supports downloading of full channels or playlists. Some paid programs may be able to download content from specific services that are not supported in JDownloader 2, but for YouTube which is widely used and cited it is a fully operational freee alternative.

JDownloader 2 also supports download of playlists or entire channels from YouTube.

JDownloader 2 comes with a "monitor clipboard" feature which is activated by default. This means that one can for example, browse for relevant dontent, and then copy all tabs with a tab copier when ready. All the URLs you have found will now be added to JDownloader 2 and ready for download. Of course, be wary that you do not start downloads larger than your hard drive capacity.

Note: Tab copiers are useful browser plugins, for example TabCopy for Chrome, or Copy All Tab Urls for Mozilla Firefox.

Java installer (if needed): https://www.java.com/en/download/
JDownloader 2 download page: https://jdownloader.org/download/index