That’s really an overly exaggerated statement echoed on the media: The survey is not a global survey on Paypal users (even if it is delimited to the USA), but rather subject to Mizuho Securities USA customers, as is inferred by the references left below, and carried out on 380 "users" (stated on Coindesk’s link).

In other words, they have an interesting perspective of what their customers are doing, but that is a biased group, and does not have enough selection entropy to allow for the concession of the headlines outside the scope of the bank itself (the size of the survey pool is also questionable).

See:
https://twitter.com/michaelsantoli/status/1333772425448796163
https://www.coindesk.com/mizuho-paypal-bitcoin-survey