Chrome uses an DMG, and the result is that people are using ancient versions of it straight out of their Downloads or Desktop folders.

Zoom uses an .pkg, and have now removed the one-click install script. So every update to Zoom now runs through the same multi-step Next process as well (with one of the steps inactive until you select your disk, as is customary). If you think that isn't a problem for users, you've never walked grandma through the steps while she's trying to show her screen though the phone to you.