I used to be a big proponent of hi-viz clothing/etc.
But for years I've been almost exclusively riding CrazyBike2, which has a semirecumbent seat that hides almost all of my body/clothing from behind, and because of that I stopped wearing the dayglo vests and stuff--it was just more to put on and make me hot, so....
When I wasn't riding that one, I was riding a trike that has a similar seat, and similar occlusion. (Delta Tripper)
Now, both of these have at least motorcycle-class lighting used day/night, plus downlighting that makes them "bigger" at night by lighting up the road around them.
Then I have a standard orange SMV sign attached to the back of each (actually just one I move between them, but...).
Then I have reflective tape (yellow/black on sides and front, as well as white strips on front-facing surfaces; red/white on back and red strips on rear-facing surfaces) on CrazyBike2. The back of CB2 presently looks like some of the signs indicating things you ought not to run into if you value your vehicle and life, and probably help more than any clothing would.
Delta Tripper has less solid surfaces to attach that stuff to, so it only has a few bits of white facing front, and red facing rear.
Both of them are also significantly larger than a typical bicycle, and are thus more visible on their own.
So, while I'm not depending on clothing for visibility, I do still make sure I'm visible.
Then, I ride to make sure I am seen, *and* I also assume that I am invisible, because there *are* still the occasional people (drivers, pedestrians, cyclists) that "didn't see me" even under conditions where they'd've had to have their eyes removed to not see me. But while their eyes almsot certainly saw me, their brain probably wasn't paying attention to any of that.
I always make sure I have somewhere to go if the traffic around me does something stupid, and if it gets crowded enough I'll pick a different route rather than risk it. I also make sure that I'm watching all the pedestrians and other sidewalk traffic, and driveways, and ensure I have somewhere to go when THEY do soemthing stupid, like step out right in front of me.
I also make sure I'm not actually where I coudl hit them if they did--I don't ride in the bike lane (or area if it's unmarked) itself if there's a chance of something popping out into it, car or bike or pedestrian. I ride in the middle of the regular lane instead, so I can dodge left or right as needed (since these things usually happen with essentially zero time for braking, even at only 15MPH, and I typically cruise at 18-just under 20MPH.
This also helps me avoid doorings, cuz that's something else that's a common problem--bike lanes striped rigth up to the doors of parked cars.
It comes down to: If there's a risk, I don't ride there.
If I *have* to ride there, I'll do everything I can to not be there when the risk is bad, or ride slower or whatever to give more reaction time, etc.
Being visible helps, but only if others are paying attention. If a person can hit (or step out in front of) a huge city bus because they "didn't see it" under conditions that make that extremely unlikely, then they probably weren't paying attention to their surroundings. And that's a pretty common condition for poeple in general, whether walking, riding, or driving.
One thing I will say about clothing/etc for visibility: In my experiences over the years, I have noticed that when I or others were riding regular bikes, and our clothes and hat or helmet (if any) matched our bike color, we were noticed more than if we had disparate colors on everything.
Dayglo colors were noticed more than regular ones, but any solid color scheme that wasn't the same as the background, or all black/dark grey/etc., worked pretty well vs mismatched colros on things.
It also worked better if your rims/spokes/hubs were also colored the same as the bike.
Basically, it made you look "bigger" as a single larger object to the first glance of the eye, vs several smaller less-consequential objects of different colors.
A month or so ago, I finally painted CrazyBike2 all one color (other than the reflective areas and teh brown seat mesh), and it is MUCH more visible than when it was a bunch of different colors. Even though now it's frame is exposed and "hollow" between the tubes, vs it being covered wtih coroplast and pictures and stuff that "filled" those spaces, it still looks "bigger" now. I'm sure the red coloration has something to do with it, but I think I could've used almost any solid color and it would have helped.
More people notice it, more people comment on it, and more people pay attention to it.