Okay so your random HR person at a nontechnical small to medium sized business now is on the line for developing spreadsheets to manage scheduling.
OR they need to maintain a set of activity codes and a timesheet outlining how many hours (or partial hours) each week are spent on what types of tasks.
It's unnecessary complexity if you want to be in actual compliance with the tax code vs just guessing whether XYZ task is on one side of the line vs the other and hoping it doesn't come back to bite you later.
I'm pretty sure it's because other industries wondered why they were having to spread such costs over 5 years while software firms were able to write them all down at once. It's not that I have a strong opinion about this either way (I'm not running or employed in a business where this matters), but that ultimately this is a philosophical argument. There isn't an objectively correct way to do this, how you view it is down to what your economic interests happen to be.
It's the other way around. Software used to be special, in that money the company spent to improve its internal processes by, say, buying a calculator had to be amortized, while money spent on developing software automation were not.
What if they literally just write a post-it note of how to perform certain actions? Are those 5 minutes capital investment? The information on that scrap of paper is subject to copyright and is a company asset in just the same way as a script. Where do they draw the line?
A minute or two (or even 10 minutes) per month is basically just guessing/bullshitting. Anything that is accurate rather than imagination requires more overhead than this. Likely anything even remotely accurate requires the sort of micromanagement software that lawyers use to track billable hours, requires desktop-surveillance, and meeting minutes-dissection after-the-fact. Not sure how they will decide to rate reddit doomscrolling when tax season rolls around either, which if we're honest, is some significant fraction of our in-office hours (hell, strangely, some of that time is when I figure out the tricky stuff).
Government wants a number -- they get a number. How I get to the number is precise enough in my opinion and you are free to disagree with my methodology.
When I was doing it, I worked in an actual startup and granularity of time allocation was in weeks. This week I was doing the thing, the other I was mostly doing bugfixes/refactorings etc.
You could do more precise and account with hour or minute granularity with tools if you have to
What about HR, etc who use excel documents?
IF they are using it rather than developing it, no. If they put in 5 hours a week writing code, yes for those 5 hours. This isn't hard.