The bubbles are entirely different. In dot com days companies were founded, funded and even IPO'ed with no business plans, few/no customers, no product-market fit and mostly grounded in "build it and they will come" notion. Quite a large proportion of dot coms was made up of companies that should never have been companies in the first place.

While there has certainly been some optimistic investment (looking at crypto in particular), the problems are nowhere near as systemic as they were in 2000. By and large, companies have products, products have customers, customers pay money. Clearly valuations have run way too high and are correcting, but it's a different unwinding process vs "umm, turns out there's nothing here."