” ... when many tech stocks lost 90% to 99% of their pre-bubble value ... “
From your chart the NASDAQ composite post-bubble was up compared to pre-bubble.
Reversion to Mean.
But trillions of value and hundreds or thousands of companies were wiped out. Probably justifiably so. Just like the current EV bubble. The only difference is that very few tech companies were producing hardware products. It was relatively easy to build a company without any infrastructure cost of manufacturing. Making EVs is a lot harder, more complex, and a lot more costly...but the same market dynamics are at work. We passed Peak Euphoria.