Are collars normal for cats in the UK?

I had previously assumed that the done thing was to put a collar on your cat so people know it's owned, but the estate I'm living on has several cats and only mine have collars. I've just found out that a cat I thought was a stray is actually newly adopted by a neighbour, the day before I was going to start trying to trap it.

It just seems ridiculous to me to risk your cat getting picked up by strangers and have to go pick them up from a vet once they finally contact you off the microchip, not to mention the stress to the cat. Am I the weird one here?