Sweating hoses

I've run into this. In a former life, I spent over 15 years selling car/ truck parts and heavy hardware. Even "back then" (out in the 80's) before "the Chinese" got involved, I saw stuff I did not like

I had about a 3" long piece of Gates fuel hose between the filter and carb FAIL after a year and started an underhood fire. It did not damage the exterior paint, but made a minor mess under neath, and damaged some wiring.

Lots of hose....heater, general purpose, fuel, I've seen was somewhat sticky like that.

Sorry after all this BS I have no idea what causes it.