Whilst premiums do seem to increase significantly there are so many companies out there and so many price comparison sites that it is a very competitive market. I find it difficult to see how car insurance can be profitable given that a tiny bump can cost several hundred pounds and any accident involving personal injury can cost thousands. I've seen many cases where personal injury settlements have been several million pounds - it takes a lot of policies to pay for a million pound claim. There's a lot of fraudelent claims/staged accidents too, plus the levy we have to pay for all those uninsured drivers
If the insurance companies generally were making a fortune surely new competitors would step in and be able to take a good market share.
Sorry, I know I won't get much support for defending insurers!