I can only guess - after you cross 25 years of age, I have never heard of insurance going down. I know people who are 50-60 years old, with zero claims ever, and they never get a discount, the annual renewal always come back higher. So what they do? They move every year. Every single year, they go through the effort of calling few insurers to get marginally better price to avoid the inevitable hike.

I can only guess that if you are rich then you don't care - it's more likely you will stay with the same insurer because it's not worth your time to be looking elsewhere.