If a person starts work at 20yrs old, averaging 2% inflation across 35yrs, at age 55 they'd need to have *doubled* their income just to have the *same* as when they were 20 and what they made at 20 would buy them half what it could then, at 55.
Then at age 90 (another 35 yrs with avg 2% inflation across the period) their purchasing power *halves again* so their #pension needs to be *double* their salary at 55 to maintain their same standard of living they had at 55.
That is 'why Bitcoin'. And why central banks aim for 2% but *won't* say why.