I went through my subscription list on FreeTube and filtered these out (the list was much lengthier initially :p)

• Alt Shift X — well detailed and narrated videos about fantasy series such as Dune, ASOIAF.
• Captain Disillusion — very well made videos about VFX.
• Computerphile — computer science twin of Numberphile; neat videos about the field with a wide range of guests.
• EthosLab — pretty much the only Minecraft creator I still watch; witty, quiet and virtually the same for a long time.
• hbomberguy — well known video essayist, easily one of the best in the platform
• Jacob Geller — another quality essayist, exploring different themes, such as horror
• Lemino — very well known creator focusing on mysteries, with incredible narration and stunning visuals
• LockPickingLawyer — very simple, to the point and informative channel about locks and lockpicking; also virtually unchanged for years
• Oversimplified — great overviews of major history events and periods, with funny narration and visuals
• Tantacrul — fairly unknown essayist on music, with well researched material and nice takes :P
• Then & Now — possibly my favorite atm (alongside hbomberguy); extremely well researched and presented video essays about history, politics and philosophy; very underrated imo