> Russia and US ULA are flying rockets from 50 years ago with minimal updates.
Old Babushka proverb, if complicated explosion related plumbing is working as intended, best not to completely rework it for sake of changelog.
Minimal updates to the shape, maybe?
But I bet the electronics and manufacturing have seen steady improvements over that time.
SLS does feel quite like a pork barrel, but I understand the funding of it along with the other commercial companies as "more options, less risk", if something grounds the Dragon capsules, having a "home" alternative instead of buying seats on a foreign rocket makes sense.