I suspect that the HN crowd is somehow insulated from the river of crap and fraud that is the internet experience for a majority of the population.
Also putting QR codes before every webpage doesn't make the web less shitty. It obviously makes it more shitty. And this will 100% be used for fraud. Phishing websites can get away with QR codes now, great.
> Just run an ad blocker,
This reads as "I am fine, so you should be fine". The median internet user has a phone so chock full of cancerous malware.
And if a tool gets good enough to interfere with tech firms ad revenue, they find ways to stop it. See whats happening to ad blockers.