This is not a physical phenomenon: the software does not actually decay, but rather suffers from a lack of being responsive and updated with respect to the changing environment in which it resides.

I don't doubt that we will soon treat the process of logging in as a figurative point of entry, meaning that log into will make full conceptual sense (cf you don't physically delve into a problem or pile into an argument, yet both are correct grammatically because they are semantically [i.e. figuratively])

By extension, a situation in which problems continue to arise faster than one is able to solve or cope with them, resulting in piecemeal, incomplete, or temporary results.

Marginalize provides a striking case of how thoroughly the figurative use of a word can take over the literal one.

Now, if we think of the tasks that we perform throughout the day as consuming separate "bands" of time, then the term makes perfect sense. Being "out of bandwidth" would indicate that you do not have enough unallocated "bands of time" in your day to complete the task. Using the term bandwidth to describe time maps more closely (in my opinion) to the original definition, than the current definition describing data capacity does.

I may be living in a bubble, but my impression is that don't understand that figurative use of bandwidth are way out of the loop.