How does the economy work without inflation?

So I was thinking about bitcoin lately, and one of its premises is that its deflationary.

In our current economy, inflation in a way promotes productivity, by forcing you to make more since saving it wont help.

Im not saying its right, but in a way it does move humanity forward.

In a world where bitcoin prevails, everyone will work for a while, and then keep their savings in a bag, because the savings will either not lose the value, or the value will even go up in the future.

Does this not make everyone stop being productive?

How would the economy work differently in the future due to bitcoin adoption?