Think of a research lab as a company that gets paid per prototype and then has to market the concept for the next prototype in an infinite loop. If you can't package up what you're doing into a sequence of small prototypes then you're not getting paid.
You can't expect the results to be reproductible 20 years later otherways.
Speaking of, I haven't played with R - what are its standard methods for handling dependencies? I'm particularly enamored of the pip and npm way of doing it, where you create a version-controlled artifact (requirements.txt and packages.json, respectively) that defines your dependencies. Does R not have a similar system, or do people just not use it?
I'm a bit bitter about the whole "writing reproducible code in R", as I'm currently wasting a lot of time trying to get R code I wrote at the start of my PhD to run again now I'm writing up.