It's called fractional reserve banking, and conspiracy theorists have been talking about how utterly fucked the banking system is for years.
I'd guess there's going to be a collapse of the USD and it will have more impact than 10 global pandemics rolled into one.
If the mainstream financial industry collapses in a way much larger than the GFC, then cryptocurrencies will see a huge (HUGE) amount of investment.
Same thing happened in Cyprus in 2013 (leading to the March bull run in 2013) and also in Venezuela over the past years. Mainstream financial collapse = people massively diverted their money into Bitcoin both times.
It will happen the same way when the USD collapses. All the unrest in the US is the catalyst, it will be too much for the US economy to take and will spark an enormous financial collapse. GFC was just based on years of inflating the economy with shitty house loans and look at the global impact that had. This is based on the fundamental value of the USD, or lack thereof.