Money has been secure for literally thousands of years before PoW was invented. Sure, PoW works, but it's the most wasteful solution to the problem of securing transactions that has ever been invented in the history of the world.
And Bitcoin will not protect anyone from non-financial inflation, such as rising energy prices causing a rise in prices for most other goods. If anything, Bitcoin would make kt harder to actually transact in this type of market potentially leading to problems of simply there not being enough money for the economy to function.
Finally, while Bitcoin may give some protection from a hostile government, it also leaves you with no protection for much more common cases of fraud, forgotten/destroyed passwords etc. Not to mention, most people transact Bitcoin through an exchange, the equivalent of a bank, which could probably be forced to cede control of "your" wallet to a government just as much as any other financial institution.
What's being "validated" by PoW mining is that someone has done a bunch of expensive, energy-intensive work on a block of transactions to satisfy an arbitrary condition (that a hash of the block be less than a target value). Explaining how this actually "secures the transactions" involves a great deal more hand-waving.
It's basically like heating your home by adding CPUs in your walls and having them compute the digits of Pi instead of running current through a resistor, because you don't want to have to trust Big Resistor.
The bitcoin network is far more centralized than traditional payment systems, many orders of magnitude slower, and it uses as much electrical energy as entire countries to achieve this.