I think the most common reason is that insurance companies try to attract new customers with lower rates / discounts and welcome gifts. Switching every year means a new insurance company spends their acquisition money on you every year.
The product the OP is talking about made quite a buzz in the business when it was first released (I do think it came out for a while). It was a price comparison tool, and the reason it failed was because it was hard to get the big brand names on board. The big brand names didn’t want to compete on price alone, because they spent so much money on their brand. They already had a ton of customers coming straight to their website.
Sorry for any formatting or spelling issues here, I’m using voice to text.
In fact they're actuarially very, very boring!