Then they should be held accountable for their choice not to vet ads they send to their users. If this was enforced legally, a bunch of companies would suddenly be able to invest the "infinite time" required to register a damn click.

That's obviously not the hard part.

"The hard part" can still be outsourced to a third party without resorting to redirection chains, either by sending the click information to them on the server-side or by sending it client side using a script.

Either way, "the hard part" is generally undesirable to users because it compromises their privacy in order to manipulate them.