Well yeah. (I don't think children should be on social media at all. I barely think it's suitable for human consumption).
I v much doubt any kids are finding nostr actually (nor adults again lol).
But yeah there are kids up to a certain age who should and can realistically have their internet usage monitored /supervised. After a certain age it is much harder.
If you look at twitter and even the most used/moderated - Instagram, you will find way worse stuff than I've seen here. Obviously they're not supposed to be on these platforms, but they are. Same with movies.
I don't really know what the answer to that is. ¯\_(ツ)_/¯
There's also a case of people actually being in a workplace who don't want to get sacked whilst they mill about on nostr. But Amethyst hiding N sf w and Nostrudel blurred image default, probably solve that.
I forgot why I was typing this.