I don't pay much attention to fundamentals, but reading what you wrote made me remember what Wolf said in his article about why he shorted the market. Its about Apple.
"Mega-weight in the indices, Apple, is a good example: shares soared 84% in the year, though its revenues ticked up only 2%. This is not a growth story. This is an exuberance story where nothing that happens in reality – such as lacking revenue growth – matters, as we’re now told by enthusiastic crowds everywhere."
https://wolfstreet.com/2019/12/30/i...-stocks-again-just-shorted-the-entire-market/
So I'm not really sure about this earnings expansion you talk about. People are trying to justify new equity highs in all sorts of different ways, and who am I to say that they are wrong. Maybe P/E ratios don't have to be at a historical 12 or whatever it is. Maybe 50 is just fine. Maybe companies don't ever have to make a profit and have sky high valuations since one day they will save the planet.
The only functioning part of the market that I see, since you bring this up, is that there is a buyer for every seller, and both agree on that price at the moment. But all the reasons are a guess at best in my opinion.