It dipped significantly but this graph is at a scale that includes Tsarist Russia where people were serfs with no access to medicine in a pre-industrial society. Having some extremely basic stuff like food and vaccines makes it virtually impossible to get that low again (unless you're being invaded by Nazis).

Have you seen the scale? There's a 5 year drop starting in 1991. It's not as massive as the gains made under communism, but it's a very significant reduction in life expectancy.