Most states have cottage food laws, with basic regulations for small-scale commercial production. E.g. you need to take a course on food safety, you need your water tested, and you can only sell up to $X per year, but you aren't subject to random inspections. There is no reason why the web shouldn't be regulated similarly, with different rules based on the size of the audience.
If we have different rules depending on scale, how is it OK for the rules for large scale social media platforms to be impossible to comply with by large scale social media platforms?
In practice though, it's not unreasonable to say that we should expect more from companies that can cause harms at a much larger scale. Perhaps there's some kind of threshold where we can accept some harm being done at a small scale while still not allowing harm at a much larger scale. Seems fair enough.