Maybe we don't always enter things twice, but verification is still a major part of software engineering.
A lot of pure data entry is still done by double keying, which is to say, the data is entered twice by two different people and the results compared to try to reduce the error rate.
As for programming, if you do it properly, there are code reviews and unit tests and integration tests and system tests. One of the few real innovations in programming since I started professionally in 1987 is "continuous integration" (which isn't really continuous, but never mind), where any change a programmer makes and commits to the codebase is automatically compiled and tested.
So maybe we don't always literally check everything twice, but our modern verification methods are fairly robust and do not represent a backward step since the 1960's.
PS we are also often required to enter an email address twice (which really annoys me since I always copy-paste it), so passwords aren't the only things.
Ironically, my answer contained at least one typo. Maybe I should have checked it.