The Wikipedia article is wrong - it only talks about "the capacitor plague" of water-based elcos from 1999 onwards.
There have been multiple capacitor plagues. E.g. in the late 80s/early 90s SMD electrolytics entered the market and these had absolutely atrocious reliability because their lead seals kept failing, so they'd empty their electrolyte into the PCB. Before that the Japanese brands had a plague. Philips "blue axials" had a plague in the 70s/80s. I don't remember the brand right now (small, red-cased caps), which also had a plague in the 80s. Rifa MP safety caps have had moisture ingress issues and associated explosion and fire issues since forever.
There have been multiple capacitor plagues. E.g. in the late 80s/early 90s SMD electrolytics entered the market and these had absolutely atrocious reliability because their lead seals kept failing, so they'd empty their electrolyte into the PCB. Before that the Japanese brands had a plague. Philips "blue axials" had a plague in the 70s/80s. I don't remember the brand right now (small, red-cased caps), which also had a plague in the 80s. Rifa MP safety caps have had moisture ingress issues and associated explosion and fire issues since forever.