Comment by ryandrake
For a lot of things, especially in bigger companies, a programming task could take 4 weeks, where the coding is only 2 days of work. The rest is spent on writing docs, ticking checkboxes in some internal release tool, and waiting, waiting, waiting for approval from code reviewers and multiple gatekeepers. I've seen a 5 minute programming task take a month to deploy because the privacy and legal approvers were on three week vacations, and the project couldn't go live until their feedback was given (and possibly resulted in code changes).
Sure, but usually these things can be accelerated if you are blocked and can't do other work. It's usually expected that you are doing other work while waiting, be it ops, reviews, invention/simplification, design, coding for other projects, or networking with coworkers etc. It's not uncommon for a firm to be amendable to spending some portion of time on outside activities such as education, event planning, or (sometimes) a side business/startup.
If everyone is spending 5 minutes working every 4 weeks... why would you hire extra people outside of contingency coverage?