Probably, but basing your analysis on 2018, to demonstrate there's currently an aging trend is straight up false, and unproductive, in that it completely dismisses the main lever to actually move the needle left: people like AOC.
It's a data point towards explaining why the Democrat party of the last 30 years has been center-right. They've always been more interested in representing the older conservative vote that has money. It's a data point towards helping explain why AOC even has to put out this statement.
The issues we're talking about are generational, so it would be idiotic to dismiss what congress looked like just literally a year and a half ago. it will take at least another decade of AOCs to even tilt the Democratic party back towards its pre- 1970s Realignment ideals.