it is difficult to respond in short.
A 5th string (in my case a 6th) more than providing extra range (5 semitones) what it provides is a couple of extra positions.
I can play the low E and the low D positions just like you play A and G on a 4-string Bass.
It also achieves positions like F #, G, A, and has horizontal margin towards other strings to phrase without having to change positions.
It depends on the song, but my tonic is usually between fret 3 and fret 7, regardless of the string.
Playing a 5-string bass is easier than playing a 4-string bass.
5 strings is a good stopping point.
Continuing to 6 strings is if you are going to come out of the orthodox role of the bass.
Actually, in my opinion, all that matters is what range you have between frets 3 and 9 on a long scale or between 3 and 7 on a short scale.
Cheers!