There are some things which you could try regulating: for example, a lot of what drives the dubious aspects comes back to algorithmic promotion maximizing time on site and advertising views. Legislators could ban algorithmic promotion for children, require companies to identify and curb addictive levels of consumption, or require companies to put more effort into moderation on the posts & comments which they promote.
Similarly, I believe at least some countries are exploring requirements to clearly indicate photos which have been modified or retouched.