You prosecute one case at a time. A judgement against TikTok (arguably the largest example) will make similar judgements against others easier.

Also, LSD isn't addictive in any sense of the word.

We don't need to know the exact boundaries of what's acceptable to recognize obviously harmful behavior and make efforts to stop it on a societal level.

This is the classic "perfect is the enemy of the good" type scenario.

Let's make imperfect progress if that is what we're currently capable of.