In the modern age, I would open google maps (where companies can, for free, volunteer to be listed), or google.com and search.
The yellow pages are ads, and in a sense a company having a webpage which is indexed by google is advertising, but advertising in an index of services is wildly different from paying an influencer on tiktok to do a dance video that just happens to have a tree stump being removed in the background, as if by accident, with the company name visible.
I think anti-advertising people are largely fine with a yellow-pages-like list of companies, with a search engine that indexes company websites, with word-of-mouth questions and reports about what services exist out there.
Will it be harder for a new company that spends $10 on a purse made in vietnam and $20MM on advertising to convince consumers it's a necessary fashion item worth $20k to take off? Yes, absolutely. Will it be harder for a plumber in my area to get business? Honestly, probably about the same, people who need a plumber will usually look at the list of businesses offering the service in their area, and a new plumber can easily get added to google maps and slap together a site.