Twitter would be king without Elon but that's another story. 
It's amazing though that instead of trying to amend the protocol's flaws the usual answer is "it is so by design" and the solution is for example "use many clients". And I say this respectfully and fully acknowledging the huge work you pour in here. You just can't expect the average user to use three clients just to see if someone mentioned him/her. 

 But this is not a protocol flaw. Every client is doing a different thing. And that is why we are here. To get multiple types of experiences. We don't want them to all do the same thing.