What Obama did with the NSA is also a doesn't have any bearing on this issue, if the NSA surveillance is warrantless it's another issue as far as sharing the contents of the in interception with other agencies well it's again a different issue.
But again this isn't about the NSA, this isn't even about the US the question is and always was what makes WhatsApp any different than a phone call? Your mobile provider by law must provide LEI of data, voice and text, now no one uses voice anymore, most people don't even text not without using alternative apps like WhatsApp or iMessage.
So what is so special about these apps that the laws don't apply to them? and if we are using encryption as a way to back out of the rights we as a society already granted our government then by all means let's do it publicly because there is no reason why the government should be able to tap the phone of a 90 year old grandmother but not yours just because you know how to use WhatsApp.
>Like it may have been "helpful", but how much damage did that lack of privacy and the existence of backdoors caused, too?
Practically none, every telecommunication equipment in the US and the west in large has LEI backdoors built-in these aren't used for exploitation, just like the fact that most mobile phones can be easily tapped by anyone with a $100 worth of SDR equipment.
While these are technically a risk in practice they aren't really a risk because they still have a high barrier for entry, high risk, and essentially very low reward due to the lack of scalability.
This has everything to do with the US, and the NSA, because the legislation in question is part of a broader campaign orchestrated by the Five Eyes.[1]
[1] https://www.homeaffairs.gov.au/about/national-security/five-...
Digital data is actually afforded even fewer protections than your example of letters in the mail.
Yes, all changes are tiny/gradual and the huge effect they have in combination with all others can often only be seen in retrospect. That's what makes your "this barely changes anything, it was always this way" argument usually so hard to argue against. But in this case it is obvious how our lives are becoming more and more digital...
And 10 years later when people wake up to it they come out and say "but we've been using this for a decade and it's been so helpful in our investigations!". And even if that was true, often they don't provide real proof, and also the government is almost never interested in doing a cost-benefit analysis for such things. Like it may have been "helpful", but how much damage did that lack of privacy and the existence of backdoors caused, too?