This makes no sense. Why doesn’t the “underlying value” of tulips change?

“Underlying value” is a meaningless word btw

Things don't have any inherent value. It is priced at a level that a buyer thinks it is worth.

A gallon of oil can be $3 or $6 depending on whether someone is willing to pay. It can also be $10 but only if people are willing to buy it at $10 if not "prices will come down to match the demand" - another way of saying it would be $9..$8...$7...$6 until it matches a buyer at which point gas is $6.

The underlying value of a tulip is the same as it was in 2000 and 2026. The underlying value of Google is much different in that same time frame.