It’s more of a major goof on googles part than anything bad. These big prudish companies will start to pull ads if they think their brand is at risk. Apple has had rumors of expanding their ad network so if Google keeps slipping they might step in.
The headline leaves out the most important part. Ads aren't only being shown on porn sites, but they're also appearing on websites that are hosted by sanctioned countries (eg, Russia). If those websites are getting kickbacks from Google, that violates laws. The EU is already investigating it.
Because the porn industry is rife with exploitation and trafficking and underage individuals and exploiting addictions and sexual abuse?? Come on it's not that difficult to put the pieces together.