Interestingly enough, I remember when I played baritone sax in Jr H.S. for a short time, the teacher said that if you "mastered" the baritone, you could also "play" the alto because it's the same fingering. Also, if you "mastered" the tenor, you could "play" the soprano. But he did emphasize that one should be "mastered" before just "playing" the other. It took me many years before I understood the difference between "mastering" and "playing".
FF
I think one way to apply "woodwinds" (especially saxophones) to this topic is this:
All saxes have the same fingering. The major sound, besides tone, difference is what key it's in (Baritone and Alto in Eb, Tenor and Soprano in Bb). The lowest sounding pitch of a Tenor is concert Ab, and the lowest for Baritone is Db. There's a technique difference in terms of changing your embouchure (how you blow into the mouthpiece).
For sake of this topic, think of the Tenor as a E-string and Baritone as the B-string. A Baritone
can play the same notes as the Tenor, and go lower, but will sound different in tonal characteristics. It's heavier. It takes more air to play. So a Tenor Sax player might think, "Why would I ever switch to Baritone? I don't need those low notes, more expensive, and it's too heavy to lug around." However, there
is music that takes advantage of the Baritones low notes and tone. Just as there
is music that takes advantage of the low-B string's range and tone.
Obviously, the same applies with the other saxes too. "Why should I play Soprano when I already play Alto or Tenor? I don't need to hit those high notes, I think the tone is goofy (I really do), and it looks like a metal clarinet."
And then there's the rare brave saxophonist that's willing to play Bass, Contrabass, or Subcontrabass Saxophone. That's getting into the territory of basses with F# and lower strings.
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The point is regardless of your personal biases based on scientific reasoning, anecdotes, or past experiences of what basses you prefer playing, it
is a tool for music you want to play. If the 4-string suits you just fine with tone and comfort, and you learned that anymore strings would be useless to you: That's fine. Others have the need for extended ranges (up or down) for the music they play, they hopefully learned the techniques and have the appropriate gear to make sure it sounds good. That's all that matters.
Growing as a musician can encompass lots of things: technique in your preferred instrument, knowing what gear works for you and the music, understanding how to apply those techniques in the styles you play. For this topic, the OP and others learned that 4-strings work for them and they will continue to grow as musicians using those instruments. Me? I've made the decision to play multiple instruments with different numbers of strings, so I've grown accustomed to using different techniques to do so. It doesn't make me a better or worse musician, just one that has a wider range of instruments to choose.
And just in case, I used to play Clarinet, moved to Baritone sax, then to Tenor, and ended with Bass Clarinet during my woodwind days. Unfortunately now, if I ever tried it again - I would sound awful. Very awful. I would sound like a guy who knows the fretboard on bass, but couldn't pluck a string or plug it into an amp. Thankfully, no one asks for my woodwind services anymore.