I think the disabling of downvotes on Beehaw and similar instances really helps. It reduces the pile-on effect, which in turn makes people less defensive and more open to proper, good faith discussion. In general I think the solution is to not find “uplifting” communities, but rather to replace whatever communities you’re currently visiting with better equivalents. The world is not as depressing and scary when the people you’re talking to about these big issues are genuine and/or educated (and by educated I just mean “took the time to read the article before commenting”).