Do we really need anything greater than 24/96? Opinions?

No I am not a measuring guy. :) 
But I realize that my previous post sounded like one.. :(

The point with it is to point out some levels and real numbers to get a perspective of what we are talking about. When 16 bits CD bit depth is 96 dB of dynamic range.

We do not always understand what that really mean and we go into the trap and think but 20 or 24 is better and it is better to be safe than sorry. ;)
That we have already with a wide margin achieved at 16 bits.

Now I do not say that CD is be all end all, but there is other factors why a format do not sounds to our liking. But it is not whether it is 16 bits or 24 bits. That specific part is irrelevant.  :)

"We are probing the future generations. Unfortunately, but a lot of them have no real future. "
Right, so you are AI from the future and  you were after probing your future generations, so you are simply lost in time! This is 2019, and we are your past generations! So nothing is lost, just reset your PlanckTime clock and go back to the future. Or to the future past your future. Then you can fix the generations for their future future past your future.

@optimize, "But most of us thinks that more is better.
A analogy is when you parallel parking your car. The car is the whole recorded music and the space you want to park your car is the format.
If you have a big space it is easier to park but if the space is 10 m long your car (music) is still 4 m and there is 6 m of unused space. You don’t have a longer car because the space is longer.. :)"


A great analogy, and one's that easy to understand. 

The OP is correct when he says,

"Plus, I really think the recording (studio-mastering) means more to sound quality than the actual output format/resolution. I've heard excellent recorded/mastered recordings sound killer on iTunes streaming and CD." 

If you are looking for genuine sonic improvement over Redbook then remastering is where that dog is (sometimes) buried.

Masterings can and do vary considerably in end result, and this does nothing to clarify matters. For example if you were to buy Bob Dylan's Street Legal album you would be faced with a number of buying decisions before you could be sure you had the best sonic copy as this quote from Wiki makes clear. 

"The original 1978 LP credits mastering to Stan Kalina at CBS Recording Studios NY; the album was produced by Don DeVito. In 1999, Street-Legal received a special remixing and remastering job from DeVito. The newer version boasted richer sound, correcting numerous issues with the original production. The new mix was also used in a 2003 SACD reissue of Street-Legal. However the original 1978 mix was reinstated for The Complete Album Collection Vol. 1."

It all depends upon who did it, what with, and why?

For what it's worth I'd take the 1999/2003 issue over any of the others.

In my private ranking of the sound quality factors recording/mastering is third, after ear/brain and loudspeaker/room systems. And before electronics.

The parking the car analogy is actually not correct. The problem is not the original recording and it’s not the digital format. It’s the remastering or in some cases the original mastering that’s the problem. It’s the overly aggressive dynamic range compression that is the problem. They took what was originally a Cadillac and squashed it down to a VW.
Also I’m not sure I go along with somebody’s math which appears to say 144 dB is double the dynamic range of 70 dB.