Why have they been so successful? Why didn't MMS 6.0 implement everything that exists in modern chat applications. Why is Meta anything more than the anonymous humble entities producing sms and "phone" apps?
I guess because Whatsapp provides a unified and standard way to communicate between people on different provider networks / countries for free? You get groups, text/images/location sharing, video/audio calls, cross-countries, that works very reliably, and you only need internet (which can be found almost anywhere even if that's just wifi).
MMS still don't work reliably for me (lost a message just last week that someone swear to have sent). And for a long time they were not free as well.
I'm not actually suggesting using MMS. I just wanted to illustrate that we've had instant communication technology (even "rich" multi-media) long before Whatsapp etc. Why didn't the providers of that technology (telecom companies) become Meta?
The difference is that MMS/SMS is standardized and agnostic to the client interface. While WhatsApp is proprietary and monopolizes the client.
We could easily have had a "internet direct message" standard implementing most of WhatsApps features. (Wait... Isn't that SMTP?)
Maybe I'm just ignorant, but what does WhatsApp bring that let's say email++ does not have?
MMS has been exorbitantly, insanely expensive and with extremely high failure rates in much of the world until...
... actually that's still the case in varying degrees and locations. And once you've got great market penetration in an area, there's little to no reason to switch unless the competition is noticeably better, which MMS really has no claim to.
Email definitely did not. When WhatsApp was beginning its rise to domination, it was on tons of feature phones - mostly just calls, texts, and WhatsApp. Email implies a lot more general internet access than was generally supported or understood by people, since it supports arbitrary data and hosts.