Jorphdan (the ph is silent) has dozens of videos exploring the lore of the Dungeons and Dragons multiverse. Those worlds have been the setting for enough videogames that I think it applies.
You might also check out Eckhart's Ladder. He focuses primarily on Star Wars but with some digressions into Halo and other science fiction universes.
One of my personal favorite gaming essayists is Grim Beard, though his particular style may or may not gel with you. His videos are generally about a single game and often encompass a game's conception, development, gameplay, reception, and legacy. It's not exactly a lore channel, per se, but I feel like it might be in the ballpark of what you're looking for.
The Exploring Series has tons and tons of videos exploring the SCP foundation and Warhammer 40k. I never got around to reading all of the Red Sea Object stories, so I really appreciated his video about it
TheEpicNate315 has a ton of videos about The Elder Scrolls (mainly Skyrim) and Fallout (mainly Fallout 4), though many of them are just well-substantiated fan theories rather than lore
If you're interested in Skyrim, Fudgemuppet is awesome. They've made content for what must be a decade now, discussing all kinds of aspects of Elder Scrolls games with a focus on Skyrim - from lore to builds to discussions of the upcoming TES IV. Can't recommend them enough to get a good grasp on Elder Scrolls lore.
Ghostcharm is also an amazing content creator who makes, among other formats, "villainpedia" and "heropedia" entries for video game characters and explores the different facets and nuances of the discussed characters. Some of the characters are Glados from Portal, Mancar Cameron from Oblivion or even more nuanced characters like Arthas from the Warcraft series or the Daedric prince Sheogorath from the Elder Scrolls (more specifically the Shivering Isles expansion for Oblivion). Really interesting lore and analysis videos, huge recommendation.
The Tarnished Archeologist makes great Videos fokusing on elden Ring and Bloodborne. His strengh is how He intertwines the Lore with the Real word historical inspiretions and their usage in These games. The (visual) presentation is worse than other Souls Youtubers but his Script is really well done and i usually learn a lot of New Things from games where i thought i knew everything
Not games but In Deep Geek does great lore videos on lord of the rings/game of thrones/some other stuff. Also a little dry but great to listen to for background listening.
CivilizationEx does lore series on a lot of different pop culture sci-fi/fantasy properties, basically histories from beginning through the latest entries. There's series on Star Trek, Star Wars, Lord of the Rings, The Witcher, Song of Ice and Fire/Game of Thrones, and more.
A popular poke-tuber I watch who goes into interesting deep dives on the origins and inspirations for various things in Pokemon is Lockstin & Gnoggin, though I think he can go a bit too far down the rabbit hole on those origins/inspirations from time to time.