To avoid repeating the arguments, for and against, companion objects, can I just say that this was discussed ad nauseam in this thread.
The only thing I would add is that the Kotlin design team seem to be split over this issue and one prominent team member recently stated publicly that, if Kotlin were to reach version 2.0 (thereby allowing non-backwards compatible changes), he would get rid of companion objects and replace them with static members.
Personally, I would prefer to see both being supported as getting rid of companion objects now would be a huge breaking change and they do have some features which ‘normal’ static members lack.