To be fair, what other simple way is there to send a document to a contact through an e2ee channel? Mail + PGP/GPG? Wormhole?? openssl???

Sending it via WhatsApp (which also has desktop clients, btw) strikes me as a perfectly reasonable solution. (Which is somewhat of an indictment of the current state of cryptographic software, but that's a different topic.)

This exact scenario happened with me in a prior job. Invoices, payments, everything could (and sometimes was) sent through WhatsApp. It was absolutely shocking to see people do this.

Some European governments are effectively run via WhatsApp.

maybe China is right: one app to rule them all

I witnessed a cop attempting to manipulate some files I provided to him on a thumb drive. It was a slow laborious process of dragging files one at a time from the Windows image viewer to shared folder. I would have liked to just do a Ctrl-A, Ctrl-C, Ctrl-V, but that was way above his level of thinking and he didn't seem like the type who wanted an education. So I just sat there through the long, painful process--and then at the end he completely screwed up the report. Idiot.