This is speculation and pedantry, but: What if they do? What if they already weed out 90% of it, and the remaining stuff that you notice is the optimal amount given the cost to weed it out (no matter how said weeding is done).
It's the poster child for a perfect market environment, where everyone involved is simply trying to optimize their returns, and there are next to no rules. It's also full of hucksters, thieves, conmen, liars, and flat-out frauds, to the utter detriment of any legitimate commerce in the space.
The harder ones seem to be healthcare (massive info asymmetry) and anything related to pollution (externalities). The market has had time on those and not done so well.
Not the very much non-ideal, largely non-free markets we have, rife as they are with information asymmetry, non-commodity products, buyers with urgent time needs, and a host of other aspects that utterly invalidate the Free Market Will Solve Everything gospel that so many try to preach.
A competently regulated market is better than a "free" (ie, unregulated) market in nearly all situations.
Basically, classical economics is predicated on a knife-edge equilibrium that ironically needs government intervention in order to prevent people from deviating.
I generally think that a case-by-case approach, with clear avenues for both rulemaking and redress, with democratic (direct or representative) control is a good starting point for solving this conundrum.
I allude to the problem of finding market solutions for ethics problems in the last part of my previous point. Markets do not optimize for ethical behaviour. Largely because of information assymetries, largely because people are not perfectly rational agents, largely because of the power imbalance that exists in many of them, and also largely because people are poor at measuring specific examples of long-tail risk.
Good rules also reduce market friction, because they let me make reasonable assumptions, like 'This product is probably not going to kill me when used as instructed, because it adheres to X, Y, Z objective standards', instead of having to go down an endless rabbit hole of 'Buyer beware, do your own research!'