I played mostly 5-strings for years, until replacing my main 5-string with a Fender 62 reissue Precision bass, which I liked (and still do like) very much. It took a bit of time to get used to, but I don't think much of it now.
Besides the already-cited (and obviously applicable in my situation) reason of, the particular bass you want not being available in a 5-string version, one other advantage, however minute, is that string sets are a little cheaper, which is especially nice for trying out a bunch of different strings.
There are some string sets only available in 4-string sets, and even when the manufacturer makes it, if you ever need to buy locally, there's a better chance of the 4-string set being in stock.
Also, there are some pickups that are only available in 4-string configurations.
I don't know these items are worth actually owning a 4-string bass if that's not what you want. I've gotten quite used to 4 strings now, and especially appreciate the narrower necks. But there are also still times when a 5-string is called for, or even more strings than that.
Besides the already-cited (and obviously applicable in my situation) reason of, the particular bass you want not being available in a 5-string version, one other advantage, however minute, is that string sets are a little cheaper, which is especially nice for trying out a bunch of different strings.
There are some string sets only available in 4-string sets, and even when the manufacturer makes it, if you ever need to buy locally, there's a better chance of the 4-string set being in stock.
Also, there are some pickups that are only available in 4-string configurations.
I don't know these items are worth actually owning a 4-string bass if that's not what you want. I've gotten quite used to 4 strings now, and especially appreciate the narrower necks. But there are also still times when a 5-string is called for, or even more strings than that.