OP’s data is LCOE, which takes into account much more than $/MW. Rather importantly, expected operating liftetime is a major component (and historically THE major economic downside of PV).

IIRC, LCOE is calculated for utility-scale solar, which has seen a 500% decrease according to your chart.

Finally, Neither chart specifies, but if OP’s is in constant dollars and yours isn’t that would explain a lot as well.