The fear is sometimes overblown, though. It's awful for privacy, but it gets exaggerated a lot of the time, even in the comment you're replying to.

(...) enables websites to use Google's new "Topics API" to view web addresses in your browser history.

People are generally concerned because it allows a site like Petsmart.com to learn that you bank at WellsFargo.com and that you also visit Nickelodeon.com frequently.

This isn't true. Websites only see some of the topics you visit, so in this example maybe Banking (or something a little more specific like savings account), and comics and animation. Here is the list of topics.

What can you do to protect yourself? Don't use Google products or Chromium-based web browsers.

It's a good idea to stop using Google products and Chromium based web browsers, but you don't have to if you want to avoid Topics API. You can opt out of it (at least for now), and some chromium browsers like Vivaldi, Brave and Ungoogled Chromium will probably remove it from their browsers.

Imo the biggest problem with it (over other types of tracking), is that like RagnarokOnline said, any website can get the info, not just the advertisers. So say, the company you're working for could be told you're interested in Job Listings, or Retirement & Pension.