So why are you frequenting these 'trashy' sites? If you are, it must be because they offer some value, right? If you're not... then you don't see any ads from them. Someone else will, because they find value in the site.
Not really, sometimes you search for some information (camera review, headphones review, medical information, toys, whatever) and instead of landing on some site that has good information you end up on some crap site with crap content and tons of ads.
Why? Because owner of that site had resources to do SEO (if one has money, one can trick Google algorithms without much trouble). How they earned that money? Through ads, obviously.
The more ads such site has, the more revenue comes in and more money can be spend on SEO to increase revenue. And so one.
Who pays for that? Those who landed on such site, they wasted time, read some potentially infomercial content.
This ads -> money -> SEO -> more ads -> money is not particularly beneficial for the economy. This looks like one more incarnation of Gresham-Copernicus law - bad content is pushing away good content. If you spend money on content, you don't spend them on SEO, so you earn less money from ads and finally you end up on 5th Google results page and that's the end.
Because the trashy sites are also the best at SEO (and google isn't properly incentivized to punish them for their ads) so you end up seeing them by accident.
Maybe trashy is the wrong word, but rather "low-effort" or "repetitive".
A whole lot of news articles are just regurgitated Reuters or AP. There's nothing wrong with that and it is a valuable service. But I am completely indifferent to these sites existence.
The sites that I would really care about if they went under, like HN, Wikipedia, NYT, etc, either use subscriptions or are donation funded. HN has job ads but they are super low key.
