The economy is a complex animal.
Consumption drives the economy - there is no point producing
anything, goods or services, unless someone wants/needs to consume (purchase) it.
Credit is consumption brought forward (for the borrower).
Savings is consumption deferred (for the saver).
One isn't any better or worse, or more virtuous than the other,
assuming all things in moderation.
Once upon a time the banking system existed to take in savings (short term deposits) and lend money out longer term (mortgages, car loans). The latter loans were "assets" on the bank balance sheet, and they made most of their money on the interest spread, and the leverage against deposits (fractional reserves). Once upon a time...
Now the banks are transaction driven, making their money from fees, and shedding the risk of holding loan "assets" by bundling them up and selling them on to external capital providers looking for yield instruments. Deposit taking is almost irrelevant to their business now. In the ECB and SNB NIRP world, depositors pay the bank to hold their money on deposit. That is how unimportant it has become.
Recency bias plays a big role in the economy. That the savings rate went up (and total outstanding household credit declined) in the aftermath of the global financial crisis should be no surprise. Perceptions of income security are a huge driver of savings behavior. That probably explains a lot about the Millenial cohort savings rate, given the "gig economy" many of them deal with. I am the child of immigrant parents, and I have spent 42 years in the deeply cyclical hydrocarbon energy business. The volatility in job security and income stability is probably responsible for my propensity towards a high savings rate (and the reason I haven't blown the budget upgrading to a turbocharged, pressurized twin, among other things
)