You seem to be missing the collective action aspect. You’re saying the equivalent of “it doesn’t matter if I dump my car oil in the river, because it’s a negligible impact on the environment.”
It can be marginal at the individual level but very important if it scales to the societal level.
That's a fair critique of a bad analogy. But it still misses the point of the collective action problem. Consider a different analogy: you are free to burn as much fuel as you want, and individually it doesn't make much difference. But if everyone collectively takes that same stance, it leads to large negative externalities.
IMO the extreme libertarian view works fine for small groups but does not do a good job of managing collective action problems in large societies when the scope exceeds our psychological bandwidth.
Ignoring the fact that “central” planning is a nebulous and uninformative term, what do you propose when those “economic and physical” constraints are insufficient to mitigate the negative externalities of a collective action problem?
It can be marginal at the individual level but very important if it scales to the societal level.