broad, sensationalist strokes

Can you clarify what you perceive as sensationalist about what I wrote? Based on the number of upvotes this thread has, I'm not the only one that thinks this way. (My tax dollars are currently going to fighting cybercrime sponsored by Russia, fighting Russian disinformation campaigns, and providing materiel to fight the Russian military.)

I take great pride and responsibility in my critical thinking skills

Me too, but as I mentioned in another thread, the issue is that not everybody is gifted with those same critical thinking skills, and the impact on those less equipped can be catastrophic. (see: pizzagate shooting)

range of ideas acceptable to post on Lemmy were restricted to those acceptable to our mainstream media

I do think we disagree on this here - For me, mainstream media is primarily good journalism where information is fact-checked and vetted. (Don't forget there's libel laws that keep journalists in check too in most countries.) Opinions and editorials represent the views of the writers or newspaper. Every organization has a slant in what they choose to cover and find newsworthy, you just need to be aware of it. With this in mind, I don't see mainstream media as a bad thing at all or something that needs to be rebelled against. It serves a different purpose from Lemmy.

Where I see Lemmy being useful and interesting is as a news aggregator with insightful discourse in the comments that's not dominated by inauthentic behaviour. Reddit is completely flooded and driven by marketers and bots, where the content and discourse quality have become low and repetitive, which seems to be the end state of 2000-2010 era social media platform.