alt Hacker NewsGoogle doesn't show ads on navigational queries because of the potential trademark-infringement legal issues that could result from recommending a competitor when somebody searches for a trademark.
Search for [carglass], no ads. Search for [facebook], no ads. Search for [spotify], no ads. Search for [american airlines], no ads. All of these would be very desirable queries to advertise a competitor on.
(IIRC they've gone back and forth on this depending on what the lawyers thought they could get away with; ISTR when Bing launched Microsoft would run ads on [google] that pointed to Bing. It's been a long time since I've seen an ad on a navigational query though.)
As a counter example, a couple days ago I was to install DaVinci Resolve on a new windows installation, so I searched "davinci resolve." Since I was used to having adblocker, I just clicked the top result, which is titled "DaVinci Resolve" but actually takes you to some awful shady thing like wondershare or softonic/uptodown, I forgot.