I believe it's really the outcome of capitalism and greed taking something that was organic (forums and chat) and monetizing it to death. Facebook monetized your family and friends, Instagram monetized your vanity / creativity, etc.
I would agree with greed but push back on capitalism. There are many ways to be a capitalist. Greed is a common choice, but there are more humanist approaches, too.
From your example, Craigslist is itself is a capitalist institution, making >$100mm/year. Patagonia, Wikipedia, King Arthur Baking Company, Darn Tough Socks, Lodge cookware, are all capitalist too.
I think it's important for entrepreneurial-minded folks to have positive role models – it's possible to develop wealth for yourself, your customers, your employees, and your environment, and to do so with respect and dignity. In fact, a well-operated business is probably the most effective vehicle for having an outsized impact in your community, so defined.
You can see this incorporation of the internet with the classic Craiglist image: - https://scalecuts.com/wp-content/uploads/2019/04/Craigslist-... - https://mediacloud.theweek.com/image/private/s--X-WVjvBW--/f...