Both of those schools of thought are too ideological to really get to the heart of the matter. Additionally, I don't see this distinction made often enough, but bubbles and recessions are 'abnormal economics' - economic axioms still hold in abnormal situations but the situations are completely different. Trying to understand abnormal situations through ideological (i.e normative) lenses is challenging and bound to be incomplete.
'Freshwater' economics / econometrics and even complexity / system theorists have given us a lot of insights into bubble formation. Dealing with recessions is something that doesn't really have an expert consensus beyond 'avoiding obviously bad things'. Heck, go ask economists to reconcile recessions with the efficient market theory.
In terms of maturity, economics is where medicine was after people accepted Ignaz Semmelweis’ theory that doctors and surgeons should wash their hands. The consensus opinion is against things like leeching (a gold standard) and people more or less agree on the right things to optimize (low, stable inflation; lower unemployment; somewhat high reserve requirements for banks, etc.).
For anyone reading this, I recommend the book "Manias, Panics, and Crashes" it's not well organized but it's very interesting.
Bubbles have a few things in common, they're speculative in nature, they're hypergeometric, and they’re fueled by credit expansion. More or less – too much money chasing ideas that aren’t going to pay off.
I’ve been warning people about used car prices since 2015 (though I expected the prices to decline about 8 months before they did). That clearly fits the pattern – after the recession used car prices were high so banks felt it was a relatively secure loan to make, but then the volume of car credit products (loans and leases) went up and made car credit too cheap, people bought too many new cars and now those cars are starting to flood the market which is a problem because banks expected to get more money out of the cars.
There’s speculation (I think cars will be worth a lot when they’re off lease). There’s credit (here Mr. 610 FICO, you can get a new RAM). There’s hypergeometric growth (the U.S auto industry sales grew much faster than the economy – a weak case of hypergeometric growth).
And now there’s the bust. We haven’t seen panic selling yet, but we might soon.
In my opinion, the clearest sign that something’s wrong is in the bond market. Something like ¼ of the world’s government bonds have a negative interest rate. People put up money today in exchange for less money in the future, it doesn’t make sense. It’s a sign that something is seriously wrong in the world economy. Too much money chasing too few ideas. I have a heterodox view – many economists think that interest rates are too low, but I think they’re too high. The market is trying to burn off excess value that’s not being used well and world governments are trying to insolate rich people from those effects.
At the same time there’s a few trillion in negative interest rate bonds, it’s hard to raise capital to start a business. That’s messed up.
There is some hope. I think we could continue the expansion for a at least 4 more years if we overhauled the tax code, we slashed rentier’s regulations (zoning, occupational licensing, and a few more), and we opened our boarders to high performance immigrants – not drug slingers but Ph. Ds / Executives / etc.