Of course it goes down. Take a look at this chart, expand to 10y or max; inflation was about -0.75% in early 2020. In fact, it went into negative territory many times in the last decade. Prices go down during recessions, particularly.
OTOH, the Fed has goal of maintaining a 2% inflation target; so in the long run you can expect it to go up. For many many years before the pandemic, it failed to achieve that goal. Inflation was too low; which means job growth, wage growth, and gdp was below potential.
Prices are an index and very rarely is the index not at an ath. Even in The periods you mentioned, the index was only off ath for a month or 3 and that’s mostly noise from
Energy prices, so no it never reached a new equilibrium below where it was (that would be disastrous)
We have seen unemployment fall slightly below 2019 levels, but the more significant result of greater demand stimulation would have been reaching those levels of unemployment much faster, rather than taking a decade to recover from the great recession.
Best case scenario is it stops growing.