> Juniper when it came end of 90's did understand this and made even better configuration system for Junos than IOS was and still is.

"even better" is an understatement ! I was working on a dual-vendor network at the time, we ran Cisco and Juniper in parallel.

Working on Cisco always just felt like going back to the 18th century, I mean the whole candidate and active config thing alone in Junos was insanely valuable:

    show | compare  # diff the config
    commit check    # lint it
    commit confirmed 10  # apply it, but don't persist unless confirmed
    commit # confirm

Meanwhile, back in 18th century iOS land, a fat finger on the ACL would leave you with a bad day in the office until you rebooted the box via OOB.