Particularly for those living in Europe, or those that have a lot of international friends - all with phone numbers from different countries - it's a godsend. My phone bill would be ridiculous if I were texting my friends in Sweden or Brazil from my Dutch SIM. iMessage for similar reasons.
Also the group messages are great. My housemates and I all talk via a WhatsApp group. It makes it far easier to hold a coherent group conversation when some of us aren't at home. SMS would be a ballache.
Oh and GIFs, voice messages, and videos can be sent in messages. Free calling too. I can call my friends in Australia for nothing, and it's not a bullshit experience like Skype.
Yes, they do. iPhones don't seem to do that, but old GSM phones did it (like my first phone, Ericsson T20, which got released in 2000). Androids have read reports in the default message app, if I'm not mistaken.
No, they don't. The protocol supports delivery report only. And the meaning of that report isn't necessarily what you believe or wish it to be:
...the exact meaning of confirmations varies from reaching the network, to being queued for sending, to being sent, to receiving a confirmation of receipt from the target device...(https://en.wikipedia.org/wiki/SMS)
Nor does it test the recipient understanding of the content. But that's missing the point.
The app lets you know that your message delivered to the recipient and then lets you know that it was opened (not merely viewed as a notification). This is a useful feature that SMS lacks.
The point was that being displayed on my screen doesn't mean I read it. For instance, I have a problem where sometimes I'll log in to my phone and an app will be active. I don't want that app; I need to do a bank transaction. But now someone thinks their message has been read, when so far from reading it I don't even know it exists! It was just displayed on my screen for half a moment when my eyes and my attention was somewhere else. (Another common problem I have is when I send a message, and then they reply so fast that the message arrives at about the same time as I'm trying to return to the homescreen to ensure I get a notification when the message arrives. Well unfortunately the message arrived first, got marked as read and no notification exists. After twenty minutes I realise what happens but maybe I've already offended someone by "reading" their message and ignoring it.)
Delivered vs read is only accurate if you have an eye tracker.
I find services like WeChat or Line to be superior based entirely on the fact that you can have an actual username. I'm still not sure why whatsapp forces you to use and exchange long sets of numbers to get someone's contact.
Obviously WeChat is not secure in any way, though ;)
It's free (unlike SMS or MMS) and back in the day it was the only service that worked reliably on all mobile platforms and didn't use PINs or usernames--just the phone numbers in your contact list so it was plug&play: just install it and you can talk to everybody.
Also the group messages are great. My housemates and I all talk via a WhatsApp group. It makes it far easier to hold a coherent group conversation when some of us aren't at home. SMS would be a ballache.
Oh and GIFs, voice messages, and videos can be sent in messages. Free calling too. I can call my friends in Australia for nothing, and it's not a bullshit experience like Skype.
I almost never send true blue SMS any longer.