I've never touched a bass with more than 4 strings, never had the desire to. Dang near all the music I listen to or play was around before anybody thought of adding another string to an otherwise perfect instrument.
...and now for an opposing viewpoint...
I've never played a 4-string bass.
Even my electric upright has 5 strings...
My go-to is a 6-string fretless. - it gets 99% of my time.
There's a saying in the gunny world: "Beware the man who owns just one gun - he probably knows how to use it."
(Almost) everything I need to play can be found on that one instrument.
I rarely play anything below E but 5th fret B is 'home.' (Played some songs this weekend that wanted a low D and it was nice to have it...)
Don't spend much time on the high C but it stays out of my way and it's there if I need it.
I have a fretted 5 because every now and then, something from the Stanley Clarke or Marcus Miller comes up - hard to get that sound on fretless.
And a fretted 7, for that matter, because I keep thinking chords are cool and I should spend more time playing them.
Yeah, 'Jaco only needed 4' but I ain't Jaco, and my bandmates aren't Wayne Shorter and Joe Zawinul.
Use whatever works for you...