After infrastructure and DNS, I think it's the most important tool for using the internet (at least for most people in most cases). It's what most people use to actually find information. It saves me uncountable hours each year.
Need to find a phone number to a company? I don't have to guess what their domain is, I just search for "<company> Phone Number" and probably land on an "About Us" page.
Need to find an owners manual to a device? I don't need to browse for 20 minutes on the product vendor's website.
Trying to look up an error in code? I don't have to search Github, StackOverflow, Gitlab, that tiny self-hosted forum for the library throwing an error, and Reddit individually.
And ultimately, ad-supported search presents a conflict of interest: what information should the search engine return to you? A near-exact result you're looking for or advertiser-funded results to be presented first? Whoever provides search has to raise money somehow, and they aren't going to sell ads if the advertiser results are always at the bottom.
Lastly, Hackernews seems primarily geared towards North America/Western Europe/AU(?)/NZ(?). For this area, generally, $5 is not unreasonably expensive.