I know people that "post" stories on WhatsApp and use it for video conferencing very often.
Not my cup of tea, but i think those functions do get used quite often.
As much as they all copy from each other, it's never a 1:1 copy. The copy is almost always slightly inferior to the original. Even if they all had exactly the same features, they'd look or function slightly differently. I do wish they'd stop copying though. Keep them seperate because they're all meant for different purposes. At least, they used to be at one point.
While I'm no fan of the big tech hegemony, I am more than okay with multiple groups doing the same thing, or trying to iterate on the same concept.
Take Reddit and Lemmy for instance. Both are designed and structured similarly, with Lemmy iterating on Reddit. I wouldn't consider it a bad thing, and I think they're distinguishable enough from each other. It's competition and alternatives like this that prevent one company or platform from dominating one "concept"
Take YouTube for example. None of the alternatives have nearly as much of a following, and I would be happy with someone "copying" YouTube and iterating on the concept to make it better and fix the major grievances. Whether it's PeerTube or otherwise