Why? Because it can really be terrible even cringey. That's what makes improvisation and live stuff so great and these people so brave.
The show cycles from terrible to great over minutes, shows, weeks, years, decades.
But like the Commedia dell'Arte it is just timeless.
As is Green Acres, Gilligan's Island, Sanford and Son, the Stooges, etc., they are timeless as the grandest opera.
Problem is, you've got to go forward in time a thousand years to see what masterpieces they are; right now as contemporary entertainment they are all just awful.
Divine, sublime comedy.
Compare any episode of the Hillbillies with the delightful play by Pierre Carlet de Chamblain de Marivaux (1688-1763), 'La Double Inconstance' (1723):
You have Jed as The Prince, Miss Hathaway as Flaminia, Ellie Mae as Silvia, and Jethro as Monsieur Arlequin.
Every episode of the Hillbillies is perfection.