[QUESTION] Can’t understand exactly how a metronome helps your playing/rhythm

Although I’ve been practicing scales with different subdivisions using a metronome for the past month and have seen great improvement, what I can’t get my head around is how it ties into playing a solo? For example, I’m playing a slow blues and want to play three notes in a triplet feel (3 notes per click), does that mean I need to play those 3 notes ever click/drum beat (in 4/4, 4 per bar)? Clearly not since slow blues lead isn’t played like that. I hope that makes sense.