Seems like a feature that was introduced in Bitcoin for no reason.
so you don't know the use case of TimeLock and you don't even use google search, but your first conclusion is that "it was added for no reason"!!! that's not normal human behavior!
here is the first result for searching "bitcoin timelock transaction" keyword on google:
https://en.bitcoin.it/wiki/Timelock it explains where it is used and why it was added to bitcoin.