@bagder Reasons are, as so often, historical. Computer software form and best practice does in many ways originate in the US during the 1970s and 80s - right the time US copyright switched from requiring a full notice of (c) symbol, year and author to not doing so. So it comes mostly by continued practice. Mostly as US law is still case law for most parts, which means that having a classic notice may give a better standing. Then again, the year itself may only once the item gets past any of the thresholds - which are quite long by now.

So for all practical reasons, it would have been sufficient to only note the year each file was created first - removing the need for yearly updates. This gives a minimum duration of 50 (Berne) or 70 (EU/US) years after your death. That's as of now something like 2076. Sure, libcurl may be still in use by then - if we still use computers and not clay tablets again - I would think any possible dispute has been solved already :)

On a side note, the EU still recommends the use of a copyright notice: https://europa.eu/youreurope/business/running-business/intellectual-property/copyright/index_en.htm