If you deprecate an API used by other developers, then you should not work on API’s used by other developers. It’s that simple. Yes it might save a bit of time

If you deprecate an API used by other developers, then you should not work on API’s used by other developers. It’s that simple. Yes it might save a bit of time for you, but it also potentially waste orders of magnitude more time for other developers. Developers who will positively hate you for forcing them to fix something that is not a problem for them! Instead keep the old API working and make the path to upgrade easy and smooth. Your API users will love you for it.