I think for argument's sake it's not really about what the government decides is illegal or not, it's that there are some areas of "illegal" that YouTube ignore

I think for argument's sake it's not really about what the government decides is illegal or not, it's that there are some areas of "illegal" that YouTube ignores, while choosing to punish (through demonetization or sometimes deleting accounts) other perfectly legal areas. It's not strictly a free speech argument (at least for me), but the inconsistency deserves to be highlighted. Consider that snuff films are illegal regardless of their method of distribution- nobody is complaining that YouTube (and every other law-abiding distribution method) censors snuff films and nobody is crying about the First Amendment in this case. Nobody complains because there is a clear legal requirement to prohibit this content, superseding any free speech considerations. Consider a gray area- filming an activity that might be illegal depending on your location or age, such as smoking marijuana. At a federal level in the USA and in a lot of other countries this is illegal, but it's okay in some areas. YouTube is pretty lax about demonetizing or taking down videos about marijuana. Joe Rogan regularly smokes and promotes weed with guests on his podcast, but there is very little pressure on YouTube to do anything about him. Consider another scenario for comparison- simply talking about guns on your channel. Following Sandy Hook, YouTube started to demonetize channels that just talked about guns but clearly stayed within the legal bounds and did not promote unsafe or illegal behavior, and some channels have been deleted. YouTube is bowing to outside pressure without any legal requirement. And there is a clear discrepancy in who demonetization gets applied to- promoters of gun control get off scot free, but people that promote legal and responsible gun ownership get demonitized. YouTube arbitrarily deciding to do something about discussing legally owned guns but nothing about promoting a federally illegal drug is not really the hill I want to die on, but I think it illustrates the inconsistency that frustrates some people. A principled and fair censorship policy should definitely allow the gun conversation to happen if you're going to allow the marijuana conversation to happen, and I think the best way to call this out (without writing the several paragraphs above) is to talk about censoring "illegal" content.