A comparison is a useful tool, but only if you are comparing something useful.
If I try to compare my running monthly mileage now with last September / October time when I did my last marathon, then that isn’t useful due to the big changes in my health since then. If I try to compare this month with last month, then I see significant progress.
This 12 month period (Sept to Aug), I ran 399 miles compared to 820 for the same period the year before. But if I compare my health then to now, I can see the reasons why.
Comparison is pointless if I am not comparing like with like. Context and recognising progress will have much more benefit to me.
Numbers and raw data are useful, but context is the difference between data and information, and it is information that is important when you want to draw out something useful.