I've had a bit of luck finding youtubers/twitch streamers who are content to let some dead air go by if they don't have anything important to say, and definitely don't do any yelling or screaming. It's a real nice change.
Partially I'm just making this post to share the few I've been watching the most:
Jagged Appliance, a Supreme Commander player and caster.
Growling Sidewinder, a DCS pilot who goes into detail about dogfighting and BVR fighter jet tactics.
Tasteless, a Starcraft caster who plays Brood War and chess in the Korean timezone.
If you're into semi narrative based let's plays there's a guy from New Zealand called Rycon Roleplays who makes pretty chill content, plays a lot of Roguelikes/RPGs and stuff. Don't know what his politics are but he doesn't seem like an edgelord or anything, haha.