A deflationary currency means you are better off keeping your money under a mattress than using it (either as an investment or an expense).
Which means that people wanting to acquire machinery to improve their farm output, someone wanting to setup a store, or someone else wanting to do something productive with their labor will find it harder to get the funding they need.
People still need to eat and will spend to eat. You can observe this even with people who wholly live their lives on BTC and will go out of their way to avoid any other currency. The Amnish farmer will continue to plow their fields.
I am not a crypto-maxi but I do believe there is a grain of truth to the supposition that inflationary economies produce vast waste as we spend ourselves away on empty desires that make us sick.
We are spellbound to a system that wrings from us all life day by day as we toil on bullshit to sustain bullshit.
I'm no ecofascist, but this seems very evident when you juxtapose economic arguments for the necessity of keeping population growth and consumption trends positive, with ecological arguments about the harm our rampant consumption and population growth does to the environment. The economic arguments for continued growth seem paperclip maximizey.