Ray Brown once said that the key to being a great bass player is to know a lot of songs.
I suppose "great" depends a lot on how the player chooses to define it.
There are three primary musical aptitudes that go into how a given player's voice develops: pitch, tonal memory, and rhythmic memory. On those three, you kind of get what you get; until the day when we learn to alter our genetic codes. There are a couple of physical ones as well, like digital dexterity and working through tools.
Beyond that, you just have to put time in the shed. I once attended an Edgar Meyer Master Class. When the top player finished his piece, Edgar asked him how many hours a day he was practicing. The guy says 3 1/2 to 4. Edgar shakes his head and tells the guy if he wants to be competitive, he has to be thinking 10 to 12.
Which, that kind of time needs to be put into learning whatever aspects you choose to master. Running scales and arpeggios and perfecting very difficult parts is required if you want to be a virtuoso player. Learning a lot of songs and playing a lot of gigs is required if you want to know the repertoire. Both of those have value. And there are others as well. Whatever you choose, you need to think about at least two years of that kind of regimen to make progress.
Natural aptitudes are a great starting point. Most players will at last have some degree of them. But, they are just a start. Jaco got where he was going by pretty much living with his instrument. Sure he had aptitude; but, most of what you hear was hard work. Most players have a difficult time putting in that kind of commitment. I don't know many players who have actually put in 10 to 12 hours a day for two years on a given aspect of playing. You kind of have to be willing to shut off the rest of your life while you do it. And, even with aptitudes, there aren't any short cuts; because even the seemingly gifted will eventually run into their equal in aptitudes, who did choose to put the time in.
What can happen is that a player gets a certain level of capability, after which things get harder. So, it seems like nothing more will be learned. That is far from the case. That is just where things start getting interesting. It's like you've learned to talk or to write, but don't know what to talk or write about. No substitutes for patience, persistence, and accumulated wisdom. FWIW. YMMV.