Even if you're an incredibly skilled and careful rider, there are a multitude of accident types that are just completely out of your control. If you hit a diesel spill on a roundabout, the outcome is pure fate. Defensive riding only gets you so far - staying at home is the only realistic way to defend against the possibility that the driver in the next lane will spill his coffee and swerve into your path, or a driver waiting at a junction will abruptly pull out in front of you because he wasn't looking.
At least as importantly, the consequences of accidents are vastly magnified for motorcyclists. I know of people who have died in relatively low-speed crashes because they were unlucky enough to slide straight into a piece of road furniture or land head-first on a kerb. If you look at the accident statistics, a large proportion of fatalities and serious injuries involve low-powered motorcycles travelling at ordinary speeds on ordinary urban roads.
You can greatly reduce pull out crashes by "presenting" when you see waiting cars, a defensive riding technique that more or less means driving in an S so that you can be noticed.
There's a surprising amount of agency involved in crashes. Learn blind spots and stay out of them, don't ride on the side of the road, only do things cars can't do when you're 200% sure the car you're passing won't swerve/turn/overtake. This includes accelerating like a hypercar, which many motorcycles can do.
> driver in the next lane will spill his coffee and swerve into your path
You can significantly reduce that risk by simply staying away from others and avoiding situations with a large speed differential. If the lane next to you is going 20mph, don't go 40+ next to them.
There are a lot of these things you can do, that most people don't because "it's not their responsibility".
At least as importantly, the consequences of accidents are vastly magnified for motorcyclists. I know of people who have died in relatively low-speed crashes because they were unlucky enough to slide straight into a piece of road furniture or land head-first on a kerb. If you look at the accident statistics, a large proportion of fatalities and serious injuries involve low-powered motorcycles travelling at ordinary speeds on ordinary urban roads.
https://assets.publishing.service.gov.uk/government/uploads/...
https://www.gov.uk/government/statistics/reported-road-casua...