Is user retention really higher on mobile? Or is it that web users can’t be tracked so look like they drop off and come back.
I think people make too many definitive statements and bad assumptions based on what they can measure. Leaving off understanding gaps where data doesn’t exist or never will.
Measuring retention is going to be mainly useful for logged-in accounts. And that is is something that could be trivially measured and compared between platforms.
My guess based on experience in this area in other companies is that app users will report a better experience, stay much longer, and return more often.