Seems like you are comparing reaction strikes to finesse fishing which is completely different. A -rigs are the far end of the spectrum using 50-60lb braid only so they are retrievable when they snag. And they do snag often. I know anglers that use flouro on clear water due to pressure on a-rigs. I won't. I have found water that has 3-5ft visibility is where the a-rig shines. More than that istouch and go.
Line does matter as I have seen it multiple times.
Crankbaits, flouro allows deeper depth because it sinks.
Mono, best for topwater because it floats
Flouro, terrible for topwater because it sinks
Drop shot, nothing more than 6lb flouro or you're wasting time. I've drop shot side by side with 6lb and 8lb with same hook, weight, and both at same time. The 6lb outcatches 3:1.
Jigging spoons, same thing. 6lb vs 8lb (flouro) is about 10:1
Crappie jigs, 4-6lb flouro gets bites
A local crappie guide used yellow Viscious and said the color did not bother the fish. The size of the line did. I think it's a vibration thing more so than visibility and color. Fish feed off of vibration.
Just this past Saturday, I had the exact same setup on two rods with live bait for stripers. All fish caught on one rod. Both had same hook, same bait, same knot, same line, rod/reel, etc. The only difference I have found is the rod that didn't catch fish had a kink in the line.
Vibration.
It's how they feed, sense surroundings, etc.
Line does matter.