"Without music there is no way that a person or persons would know if you have taken too long on any step. It even gets better performing a group."
That is tantamount to saying that without other musicians, there is no way to tell if a soloist has played too long a note.
Which is of course outrageously rediculous!
A note or a step is too long if it puts the musician or the dancer into a position from which they cannot continue in a manner that makes musical sense. If you hold a note out and kill the music and don't have a plan for resuming, you held it too long. If you outstep your body flight and get stuck and kill the motion such that you have to muscle your way through, you have stepped to long to create music in your dancing.
Musicality is not about being a slave to the metronome, it is about creating a whole that has self-consistency as a piece of art. Each note, each step, must make sense in terms of what is around it - certainly the other notes and steps, and also the other instruments or dancers if they are involved. If no one else is involved, what you play or dance must simply make sense in the context of what you were playing or dancing an instant ago, and what you will play or dance next.