While people will always need to buy the essentials, I do buy that a deflationary currency could discourage discretionary spending. Maybe people are slightly less likely to splurge on a big purchase or a nice dinner. I don't know what the delta would be in GDP growth compared to now; it certainly could be negligible.
I've got good news for those people, you can't buy toilet paper with bitcoin today. And they aren't getting paid in bitcoin today, either. And if they tried to exchange bitcoin for fiat to buy toilet paper, they'd be subject to incredible fees that would make such a transaction pointless.