The linked article talks about misleading ads that let people download malicious apks. This is no different than scam emails with malicious .exes, or "please reset your WhatsApp password here" messages, ...etc. In other words, it doesn't demonstrate why web ads are any more susceptible to being malware vectors when compared to email, messaging apps, or social media (basically anything with user-generated/third-party content that allows text).

Which is why it feels unfair to me to single out Zoom's addition of ads to their free tier for being a malware vector.

Yeah, I agree that it's overblown.