As far as I can figure out the historical reasons, wheel size for the safety bicycle was a consideration of comfort and economy. Rough roads which were of course largely unpaved indicated wheels as large as possible, while ergonomics indicated a smaller size. So the "standard" wheel size we have is as large as can be fitted on a safety bicycle with ergonomic condiderations such as the front wheel hitting the feet. Presumably comfort was more important than economy, or economy had a fairly small impact at the time when wheel size was considered. The smaller size also necessitated some gearing system so that you don't have a stupidly fast cadence for reasonable speeds. So the whole development history stemmed from the original wheel size choice.

I haven't checked the dates, but I think at the time, the pneumatic wheel was not yet invented when the safety bicycle was invented, so the large as spossible wheel would have been chosen as of high importance due to solid tyres.

But the advent of the pneumatic tyre to a large extent neutralised the requirement of a large wheel as mathematically shown by me in the small wheel harshness thread. A very modest reduction in inflation pressure results in indistinguishable comfort response between a 16" wheel and a 700c wheel. The reduction in pressure is not so large as to put the tyre into the high rolling resistance region of operation, ie you can get comfort without sacrificing much speed at all.

So with pneumatic tyres, the only argument that can now justify the large wheel size is the one where road surface has a large scale impact on the wheel, ie bumps/holes much larger than the tyre can absorb, or soft surface where the bigger circumference would sink less into the soft surface.

One might argue about stability but I don't buy that one, based on experience backed up by a thorough understanding of the underlying reasons. Stability is much less determined by wheel size than the intricacies of geometry and weight distribution.

The other arguments are spurious, because they are more connected with what's actually available to buy, ie pre-determined by the ubiquity of larger wheels rather than a design necessity. For example, if by some historical accident a 20" wheel had been chosen as the standard, the marketplace, UCI, gearing option etc would all have centered around that size, and the "better gearing options" argument would be stood on its head.