Is it just the wealthy? In the age of cancel culture I also see individuals scouting every facet of other individuals’ lives, looking to doxx them or out them as failing some purity test. Deplatforming for political gain also is an anti privacy position. I feel like everyone, not just big corporations, is waging these battles.

It's just the wealthy who are bankrolling the capture and dismantling of government, yes. If you haven't noticed, wealthy people/corps have the most influence on policy. Deplatforming is something that happens in the realm of entertainment-politics, where the goal appears to be angering or appeasing mobs to keep people distracted from important policy issues and divided on the rest.