The example you give doesn’t really track. If a drug dealer is outside the entrance of your home it’s completely unavoidable. A kid looking at adult material online? Entirely within the control of the parents. We already have filtering and monitoring software.

I know several parents that limit screen time, require screen usage be restricted to public areas of the home, have parental controls and filtering operating etc.. some of the parents I know won’t even let their kids watch a movie unless they screen it first.