Most free web sites pay for their upkeep with ads. It has been an unwritten agreement since forever (or at least as long as there have been ads on the web) that if you consume the content, you pay the creator by looking at the ads on their site.
Consuming the content without looking at the ads is like shoplifting because you don’t like the way a store’s checkout counter works and/or the fact that they want money from you at all.
If you’ve ever managed or monitored a corporate firewall, you’re honestly doing yourself a disservice by not using an adblocker these days. The amount of malicious advertising that corporate firewalls block these days from employees on the internet is astounding.
Legitimate as traffic accounts are constantly hijacked by threat actors as its such an easy way to spread malware and compromise machines.