in my opinion it’s one of the most dangerous ways to travel due to the speed differences
There’s a sort of truth in that, but the factor of speed difference is primarily one of consequence rather than probability. So if you get hit by a fast-moving vehicle then it’s most probably going to go badly, but that’s not the same thing as the chances of that happening.
It’s a bit like being shot/stabbed/suicide-bombed/etc in the street: if it happens, you’re almost certainly screwed, but it’s almost certainly not going to happen. A serious cycling collision is a less mathematically extreme risk, but it’s still well into high-consequence/low-probability.
Obviously everyone (understandably and rightly, in the context of their own experience and behaviour) has their own way of balancing high-consequence/low-probability risks against lower-consequence and higher-probability ones. And everyone also (again understandably and rightly, in the context of their own experience and behaviour) has their own perceptions as to how high or low the probability of any given risk is.
It’s like we all know with roads: some naturally invite worse driver behaviour than others, so many of us avoid those and find different, more benign routes. If someone’s only ever experienced one or the other then they’ll have a very different view as to how “dangerous” cycling on the road is. And that’s only one factor.
The issues only really come when people start projecting their own experiences and behaviours onto others, rather than trying to abstract both/all of their viewpoints into an objective and rational approach.