My post is not trying to make your point invalid.
My point is consider your child, in the case of this thread 5 month old baby, as a person. Treat them as a person and cater to their needs. Don't treat them as an object to pump full of drugs. This is based on sitting behind parents of a baby who gave absolutely no consideration to the comfort and care of the child in any obvious way. And that made my flight hell.
I listed a number of techniques that my family successfully employed while flying and also while in situations very similar to flying - child locked up in a confided space of extended periods of time not able to move around much. Perhaps you missed that, and instead denigrated the suggestion that car travel could in anyway be similar to flying. But your "not saying I'm wrong"
As for your points: for long haul the pressure changes are a relatively short part of the flight and as I (and others) suggested give them a bottle to fix that problem.
Secondly,
I didn't stop, my wife and I employed techniques with our children in long distance car trips and
did not stop, whether we could have stopped is irrelevant. Of course, I'm not sure how stopping in the middle of the Hay Plain, or an hour out of Woomera, is going to be much better anyway. Those same techniques, as I listed in my post, were also employed while flying to good effect.
Thirdly, refer to locations mentioned in secondly, yes, of course, the A/C was on.
As for denigrating your suggestion, you admitted yourself that it is not appropriate for a baby. That is what makes your point invalid. And I didn't see many people agree with giving drugs to a 5 month old.