There really aren't that many active peertube channels. Here's all the non-linux channels I could find:
https://piefed.social/c/blitzcitydiy_channel@makertube.net - electronics and music
https://piefed.social/c/simon.caine_channel@tilvids.com - general technology
https://piefed.social/c/thunderbird_channel@tilvids.com - thunderbird email client
https://piefed.social/c/ewen@makertube.net - photography
https://piefed.social/c/icesheets_climate@tilvids.com - climate
https://piefed.social/c/shifter_cycling@video.canadiancivil.com - cycling
https://piefed.social/c/transit@video.canadiancivil.com - transit
https://piefed.social/c/urbanism@video.canadiancivil.com - urbanism
https://piefed.social/c/coreyartusimagery@makertube.net - art
https://piefed.social/c/dot_social@flipboard.video - fediverse podcast
https://piefed.social/c/thegiddystitcher@makertube.net - crafting
https://piefed.social/c/linuxappsummit@tube.kockatoo.org
https://piefed.social/c/submedia_channel@kolektiva.media - anarchy
https://piefed.social/c/solarpunk@kolektiva.media - documentaries
https://piefed.social/c/boilingsteam@peertube.linuxrocks.online - gaming
https://piefed.social/c/justsomeguy@comics.peertube.biz - comics and movies
https://piefed.social/c/comicuno@comics.peertube.biz - comics
https://piefed.social/c/blender_channel@video.blender.org - blender
https://piefed.social/c/4742f338-1ded-4798-bd85-93e8de367476@peertube.touhoppai.moe - krita tutorials