Each generation has improved somewhat. I've owned a 742 years ago. Can't think of a single reason I'd buy one over a bolt rifle. Most can be fairly reliable if fed factory loads or well made reloads within a very narrow range of pressures. And if kept very clean.
But the reality is that for "AIMED" repeat shots the difference in speed is insignificant. A semi is faster for laying down suppression fire, or in very light recoiling rifles. But not significantly faster if hunting and actually trying to hit something.
For that tiny bit of speed you get a rifle that is much heavier, less reliable, has a poor trigger that cannot be improved, at best average accuracy, and they cost more. They won't function with many hotter loads that will work just fine in any other action type.