You are correct. I rarely go the inclusive generality of all. Or everyone, etc.
Many. Too many.
And with the histories (and age, but that doesn't seem to matter that much once a history starts with each player) of Stewart and Topa, and Paddack, and now Ryan, and even Duran (so many you could list but you get the point), I do think often luck IS a major factor., if not THE major factor.
But as far as complexity, I agree. Where do you start? Hell, I think you can go all the way back to the lowering of the mound for the 1969 season to the start of noticably more pitching injuries. 15 to 10 inches is massive (and teams were notorious for cheating on that - with the Dodgers accused of being as high as 20 inches at times.) Changed release point and arm angle and all kinds of mechanics. They didn't do TJ surgeries and others before 1974. We don't really know how fast guys like Gibson and Koufax..... and Walter Johnson threw, but it is assumed that it wasn't at like today. And those guys went every 4 days. But when the arm went, the career was over, basically. The Dodgers went to 5 man rotation in the early 70s, and like the opener, teams started giving it a go, and by 1980 or so, it was standard and the pitching gospel. But the injuries didn't slow, they kept happening more often.
I don't think you can stop the injuries. Not with the speed the game calls for now. Make all the graphs and collect the data and have the gyms and pitching nerds about mechanics you want, the arm is not meant to take that much force.
So maybe back to ALL? and the real answer, in the end ..... IS that pesky luck? Very complex, for sure. No reason not to continue to explore and try, as the game becomes data driven more and more and more.