why cant we just use centuries decades
While using centuries and decades can be helpful for providing a general sense of time, they do not provide the same level of specificity as using years, months, days, and so on.
Time is a continuous and linear concept, and using smaller units like years allows us to precisely measure intervals and track changes over time. Centuries and decades represent larger chunks of time and do not capture the same level of detail.
Using smaller units also helps in organizing historical events, scientific studies, and various other activities that require accurate chronological sequencing. Such precision enables us to make meaningful comparisons, analyze trends, and identify patterns.
In certain contexts, using centuries and decades can still be useful, but for most purposes, utilizing smaller units of time is important for accuracy and clarity.