The bad ones are typically well-known desktop anti virus scanners that try to score by showing you a high number of threats they allegedly defeated. If you look at those threats in detail, they turn out to be browser cookies, or bookmarks, or something similarly trivial.

Identifying good vendors and products is generally harder. I've heard good things about canary.tools and bromium, for example. Both explain what they do in terms that don't make a techie roll their eyes (too much at least): https://canary.tools/#how-it-works and https://www.bromium.com/advanced-endpoint-security/our-techn...

A good (but not exhaustive) test is to look at what the vendors promise. If they promise you full protection of your machine or network, you know they are full of shit. If they talk only about one aspect (identifying attackers, reducing the attack surface on a browser), things start to look better.