It's not strictly a matter of conservatism, it's a matter of US values being enforced as universal; or IMO in the limit as you approach maximum size for tech companies, the most conservative values of every important market being enforced in all markets. In the US, people are freaked out about fathers kissing their sons, but fine with teenagers having things done to them on video that wouldn't occur to most people to be possible until they see them being done to someone too young to drink legally. There's also been an escalation against depictions of cigarette smoking in the US, but constant depictions of drinking which are frowned upon in large parts of the world that have no issue with smoking.

Every culture has taboos, but because of giant US internet companies mediating the content of people's communications, US taboos are currently more important than everyone else's lack of taboo. Ultimately, I see this leading to everyone's taboos becoming more important than everyone else's lack of taboo; I've heard of some of these platforms enforcing Lese Majeste laws.