Boris Gudenuf
Deity
A. If you're beaten to the start of a wonder, your lost time and investment is considerably less than if you're beaten to the end. **Considerably**. Like, practically zero. Same goes for the frustration factor. Getting beat to the end is **FAR** more frustrating.
B. Yes, lots of random libraries, pyramids, cathedrals and universities have been built throughout history, but there has only ever been ONE "Great Library", ONE "Great Pyramids of Egypt", ONE "St. Basil's Cathedral", or ONE "Oxford University". You admit yourself that these specific wonders "achieved greater fame" or were "bigger or more impressive" than their peers. In other words, they are indeed one-in-history, unique ideas. That's pretty much the definition of it.
'Practically zero' investment to start a Wonder is only true if one assumes the current Civ VI system, in which the requirements to start are having a requisite Tech or Civic and terrain/infrastructure combination, none of which are particularly exclusive. IF, to start a Pyramid, you had to have a particular type of government with a God-King ruler, easy access to 1000s of tons of several different types of stone, water transport to get the stone to the chosen site, and a readily available labor force for a large part of the year, starting a 'Wonderous' pyramid would be a much different proposition. And based on your Civ's immediate need, using all that to build a stone Long Wall for protection might be a much higher priority than a Tomb!
Also, the Pyramid of Cholulla in Mesoamerica was larger than any of the Egyptian pyramids - as they said about the chicken, it Pays To Advertise, even when it comes to 'Wonders'.
Both the Museum at Alexandria and Oxford U. when they were built were only One among Many. Their 'reputation' came long after - centuries - they were built, which makes a case not for Building Wonders, but for Developing Wonderous Attributes to an Institution.
In fact, given that Oxford was not the first European University and even later had close competitors in Cambridge, the Sorbonne, Harvard among other similar institutions, a case could be made for building a Building and 'upgrading' it into a Wonder later by some mechanism.
I agree that by definition a game must have some element of competition or its just a sandbox. The type and manner of the competition in regard to World Wonders is what is the issue here, and how to keep the competitive element without what is, IMHO, a Fantasy element of assuming that someone ever set out to build a particular type of Wonder with particular benefits IRL.