Who knows how much faster it depends on how the qbits are measured and what algorithm is used to make the factorization go faster.

Exactly my point, which is why I asked because you seemed like you knew for sure.

There are already encryption methods capable of providing more resistance against quantum attacks but updating software isn't as simple as pressing next until something is installed. These new signatures also take up more space which has implications especially for blockchains.

The biggest blockchain (Bitcoin) takes up no more than 200GB currently after 12 years of operation. each block is limited to 1mb in size, that's 6mb per hour, 144mb per day and 52GB per year, max assuming all blocks are filled.

How much more space exactly does it take? Why won't sharding and other solutions already being implemented and used on other chains work? What makes you think an update would be impossible, Bitcoin has already been forked many times. Sure all nodes must be upgraded before they can join the network, but seeing that's required to prevent theft of coins that won't be a big issue.

A quantum attack would shake the majority of peoples confidence in the entire system not just crypto. I don't think you'll see people fleeing to crypto as some sort of financial safety net. Those who remain will quickly change to blockchains that already offer quantum security not that will will matter at that point.

And that's not "fleeing to crypto" how exactly? Yes there's already cryptocurrencies using quantum resistant algorithms. Many POS coins where designed with a whole different type of algorithm, in many cases something that relies on memory. I have not yet heard of a quantum computer capable of storing more data and moving it faster than SSD disk.