Unfortunately, these laws are working exactly as intended. If they discourage all forms of sexually-explicit material, the laws are working as intended. They are not really about "protecting the children." They use that as an excuse to make it too legally risky to publish pornographic/sexual material under any circumstances.
If I was a publisher, would I trust an age-verification system to protect me from 15 years in prison or an "investigation" that results in nothing but destroying my life? Nope. So eventually the legitimate website operators just give up.
Or how about the ISP who now simply refuses to do business with any website that publishes sexual material just to avoid legal consequences for themselves?
Working as intended.