I think one of the other reasons they might seem unbeatable is because everyone who runs them is a whale with lots of power so it seems impossible to beat but a blitz team with less power can still kill tailed naruto turn 1 the issue is you need to be closer in power if you want to take one of the healers down and by the time you blitz again the poison and hokages kick prob got you.
But then its trading one problem for another immortal team for 1 shot blitz teams and we all know how much people hated tobi 1 shot meta.

I think people overestimate Roshis ability to fix everything we already have 9 tailed naruto with essentially same burn and jinchuriki chakra and does he solve it alone if you are lucky enough to have him ~? No? Plus like already been said lots of immortal teams are synonymous with a whale account so good luck using your roshi to beat someone who spent that much more.

Thats nice care to share with the rest of the class? :)

Ye beat one whale team with another whale team not really a solution there.