A routine has some laziness to it. There's less thought involved. Efficient that way. But if no thought is put into it again, it's the same thing over and over.
Actually I was already starting to branch out the routine a bit a while ao. It just becomes pretty much static over time.
Varying it with something as simple as a text file could work easily. As long as I have the text file. Planning long, long term (a week, a month, more) would be possible like that.
Even with several routines, ex. 4 routines, that would get static after a while. 20-30 routines could be good.
There's also the push element (time or number of reps). It *has* to be pushed, otherwise it's defeating the point of progress really. With no push, it's just maintaining what's already there. And if there's a push, then there's a recovery/heal time involved. Physically healing, resetting form, etc.