"Deprecated" to me means the author says you shouldn't use it, or with more nuance, that "you shouldn't start using it now, and you should switch out of it ASAP if you already are a user, because it will very possibly stop working within the lifetime of you own project".

"A better alternative" is not enough of a reason to not use another alternative, because "better" is not an absolute value and choices tend to have many axis to balance (for example, prior experience).