@DRS1970
Surely it is far cheaper to retain an existing customer, than it is to entice a new one.
Most of the insurance firms are just "shop fronts" for a very small number of actual real insurers in the background. It's all just branding. Often it's the same staff in the background doing the work, but just using different "front" names, stationery, phone numbers, email addresses, etc. The "shop front" firms just have slightly different algorithms for pricing etc, but the real firms in the background don't really care which shop front sells you the policy as they get your business anyway if you change, just from a different route!
The shop fronts don't care if you move to a different firm, as they'll have a steady stream of new customers via the comparison sites.
If you enter the same driver details onto a comparison site, but try with two different cars, you'll almost certainly find the "top 10" will be the same names, but in a different order, that's because they create artificial "points of difference" in their pricing algorithm.
My son works for one of the UK's biggest insurance firms (a "proper" firm, not a front) and he tells me which of the "fronts" use them as the real insurer - it's a lot! Even his firm "re-sell" partial blocks of policies to other "proper" insurers to spread the risk, and in turn, his firm "buy" partial blocks of policies from other proper insurers - it's just like betting shops who "place" bets with other shops to "hedge their bets".
You'd be surprised how little "genuine" competition there is in the insurance market. The comparison websites are all "smoke and mirrors" to give the illusion of lots of competition and choice, but it's not genuine!