I agree with 99% of your post. ..
Where I stray is installing the drivers on the disk first.... it just isn't worth it (to me). For over a decade now I've only used the latest and greatest and typically without issue. Note I'm also a reviewer and in that time reviewed well over 100 motherboards using that same methodology. If the process was wonky, I feel like I would have run into it, ya know?
Also, optical installations are SLOW compared to USB. Downloading MS Office (you can DL older versions as well) from the website and installing it is faster (as long as you don't have potato DL speeds,

). No media to lose/damage etc.
As far as installing from disk then updating... that wastes a lot of time to me. Whereas with downloads, they are up to date or at least don't need the full Monty over a dated disk (MS Office is a good example).
AFAIK, anything that is on the driver disk is on the website. I haven't run into anything that wasn't (though it is possible of course, lol). I know sometimes with audio the website will have the driver and then the [name here] software separate, but that is the only thing I can recall off the top of my head. I don't really use anything off the disk, honestly.
Anyhoo, to each their own. Personally, I haven't looked back for several years now. The transition off of optical media felt odd, but, you easily get used to it and the speed and convenience is the best we've got and worth it. It certainly isn't dead and there are, without a doubt, reasons to have one. The absolute nature of that post is easily disproved.
EDIT: I just realized the only optical media device I have in my house is my BR player. My family and I just got rid of a laptop that had one (3 PCs, 2 laptops).