I have always been wearing a helmet since I have started riding scoots in 1972. Open-face initially and then full-face, once I realised how much better the visor was than goggles when going fast (most of the time back then). As well as a leather jacket, quality jeans (not always), leather gloves and leather boots at least covering my ankles. That was it and has been it for all the years up to now - 49 total. I will forego the jacket when riding just in town, especially on hot days. I never wear shorts on a bike, though. I have been fortunate only to have fallen off a few times (all low-sides) in all these years and have been lucky not to have crashed into anything or to have had anything crash into me.
I have always been riding defensively - anticipating all other vehicles at interchanges, making eye contact, extensively using my mirrors and thinking for drivers in my immediate vicinity, including those behind and beside me. Even more so as I grew older and supposedly wiser. I have probably spent at least a third of my time riding as a commuter or in traffic, and invariably lane-splitting. And I keep a keen eye on all my rides - tire pressures, tread depths, and that everything works; lights, horn, brakes, etc.
So, have I really been lucky or have I been more careful/alert/prepared? I cannot say. I continue to ride fast, most of the time.
I approach each ride as a chess game - I think most of us do. Subconsciously by now in my case, of course - me against everything else on the road, including oil spills and expansion joints. Crashes forever remain the main risk - the potential check-mate call. IMHO, only two things are of undeniable benefit in a motorcycle crash (impacting something or being impacted by something - not merely falling off and sliding along) - a good helmet, preferably full face, and a neck brace. And nobody wears the latter.
I am not convinced of the street/road benefit of leather suits (especially branded ones) or adventure garb, bulky back protectors and the new craze; blow-up vests (wearable airbags) - not to be confused with blow-up dolls (-: I believe most of that is simply opportunist/innovative vendors finding new scares to extract cash from group-thinking riders, mainly n00bs. But that is me.
And it also scares new riders off, aside from no one wishing to wear all that sh1t. Especially in summer or close to home.
So, I will be sticking to my own (personally proven) formula. However, I am contemplating getting my wife a neck-brace, even though she might protest. Her latest bike jacket features an integrated low-profile back protector. And I do not allow her to wear an open-face helmet - the halfway compromise being a flip-face modular Schubert. The pillion forever constitutes the more compromised position in a motorcycle accident.