The Paradox of Thrift says that the economy would actually shrink if everyone saved to such an extent, and people would have less overall with time. Even Hayek remarked that individuals can save, not an entire country.
Imagine a pretend happyland where everyone owned their own home and had a stockpile of 30 years of food. They change their usual work week to take Mondays off and sit comfortably at home. 20% of the economy literally disappears overnight. It isn't obvious that the anyone would be suffering.
The reason the economy shrinking is so terrible is because people generally live hand-to-mouth. If you have enough resources stockpiled to last you the rest of your lifetime, you technically no longer need an economy. It is still nice to have and some resources can't actually be stockpiled (eg, a doctor's time) so I wouldn't advise doing without it, but the economy is mostly important because people don't stockpile resources.
There seems to be a feeling that we should not stockpile resources because the economy is important. That line of thinking is very popular, but imo precisely backwards. Links the right things in the wrong order. Bit of a non-sequiter, but that thinking is why governments and central banks keep printing money.
All this is an interesting but philosophical point. People, in the main, consume everything they have available to them and then work to earn more.
EDIT It is notable that if no-one borrows then by definition no-one can make money by lending money. Again, although this is radical compared to what we do now, it isn't actually obvious what the problem would be. Again, it isn't advised because borrowing money for the purpose of investment is a source of fantastic economic efficiencies. The issue is we all know there is borrowing going on to fund consumption. That isn't a good idea, although the cost is carried by the people responsible so I have no beef with it happening.
Sure there’s non perishable food. But a lot of the food people eat is perishable. They have to keep buying it.
Who is going to source the food if no one pays money to buy it? How will they pay for the operations to get the food?
Now apply this reasoning to other verticals. In many fields, the investments lead to actual improvements in technology, and increasing automation and productivity.
If everyone sits at home that only works if nothing ever breaks and no one needs improvements and technology. We’d still be using gas lamps if no one built electric stations etc.
About debt you can watch this: https://m.youtube.com/watch?v=PHe0bXAIuk0
Additionally, grace's savings, not spending money on things she did not need, increases net savings and decreases the cost of debt for those wishing to access her capital to invest in things they desire.
If grace went further still and didn't just passively SAVE her money, but actively invested it in things that made a positive contribution or spent that money only on things which made her desired world happen while discriminating against goods and businesses that made the world worse, either to fulfill her own desires for a better world or investing in such for others, she'd actively be choosing to use that money to build up capital in areas of the economy and reward sectors that supplied those things, lowering the cost of supply, and potentially creating employment in those sectors.
Either way, there are generally better things to do than consuming for the sake of consuming. And its primarily not about spending or not spending, but choosing where to spend and choosing where to invest, for an economy that keeps everyone employed but produces nothing of value (or actively produces harmful things) is not an economy anyone should be aiming for.
If we are so far down the path that we are advocating spending and consumption merely for the sake of spending and consumption to keep the economy turning over, then surely it would be better by far to advocate conscious directed spending and investment, rather than consumption.