Most UK insurers also provide other insurance products, e.g. ”Buildings and Contents Home Insurance”. Many insurance providers will give additional discounts for purchasing more than one policy with them.
By doing this you might save a reasonable amount on all your individual insurance premiums. Also, think of the potential hassle you could save yourself when renewing your car, holiday, pet, and home insurance with just one company instead of haggling with 4 different companies.
The economics don’t always justify having a single all purpose insurer, but when they do you’ll save yourself a lot of hassle and sometimes a fair bit of money into the bargain.