If all roads had a 10mph limit and we all had hi viz, all give way junctions were stops and round-a-bouts were trafic light controlled there would be no fatalities on the road. There would also be no bikes as it would be boring as hell.
I agree there's a trade-off, but you don't have to go 10mph everywhere to improve your safety margin.
If you watched or followed some very safe riders you might find they went below the speed limit in some areas e.g. schools and dangerous junctions, but you would find them to be very progressive in other areas.
Having fun and being safe are not mutually exclusive.

There was nothing within reason that I could've done to protect myself more.
I agree there are scenarios in which there is nothing you can do. If you don't accept that then you need to find other more acceptable forms of transport.
Most of us accept inherent risks all the time e.g. when we get on an aeroplance.

That doesn't mean we shouldn't try to avoid accidents for the majority of the time when they are avoidable.

At the end of the day if you don't accept the inherently dangerous nature of bike riding then you shouldn't ride a bike.
Some of us chose to ride a bike but do every thing we can to make it as safe AND enjoyable as possible.
You can have a lot of fun doing this e.g. track riding.

But where I came in, is that I don't believe you will decrease your chances of having an accident by stopping riding at 3pm on a weekend (because the most dangerous time is 3-6).
You will decrease your chances if you don't ride like the people that only go out at 3-6 on a weekend. It's not about the clock it's about how those individuals are riding.
An analogy is saying - most plane crashes happen on Tuesdays so if I don't fly on a Tuesday I'll be safer.