If that’s your experience please help everyone by telling us why you think PJSIP isn’t working for you and the details of your problems.
If those things aren’t put into a bug report either with Sangoma or Digium, unfortunately nothing will be done to improve it and in five years we’ll still be saying “PJSIP isn’t ready for prime time”.
In fact Digium receives hardly any bug reports on it, so PJSIP won’t be different a year from now if we don’t provide them any.
In fact there is a lengthy thread about PJSIP, the perception of it, and its problems: