When you're dead all your savings are worthless (to you), so your likely to spend most of them before then.If that were true, why would there be so much debate around the estate tax? Warren Buffet is a rarity. Most people want to pass money down through generations rather than spend it as they near the end of their lives. Taxes on inheritance encourages spending and charitable giving.
Some consumption cannot be postponed: you need food, a roof over your head, transportation, etc.
Given. Probably not enough to avoid depression though.
Time has value. For example, if you wait another 6 months the same amount of money (bitcoin or not) will buy you a better computer. This is likely to hold true in the foreseeable future. Still people do but computers (and phones, etc)
You seem to be arguing for deflation. Given that I can wait and get a better computer there's even less incentive to spend it today. I remember a study that showed for a computationally intense problem (many years) you could finish sooner by waiting part of the time and buying a faster computer. That's even less incentive to move money around.
There's opportunity cost: even if your savings increase in value over time, investing them in something could increase them even more.
Not if the economy is depressed.
In sum, the natural limitations you site - even if they worked - are not enough to avoid depression. A small bit of inflation is a good thing. Think of a dollar/bitcoin/whatever as a unit of work and inflation as 'urgency'. :-)