Apart from the one-stop-shop advantages of having insurances at bunq, I can't see the benefits either.
Being a fintech/bank, bunq knows two trades: technology and banking and they are superb in combining those two trades. But bunq is not yet a superb bank as they have many things to improve, they are however, well on the way and doing a very good job.
Insurance is a trade on its own and would be new to bunq. It demands a fine infrastructure and many, many resources to build such. It also demands a financial infrastructure which has to be built from scratch.
As a bunqer I would rather have bunq focus on the one thing they are doing so well at this point; developing the best banking service one could provide.
The insurance trade is, as well as the banking trade, a very competitive market and bunq is still to gain a solid market share on that market. Why would one try to gain a solid market share in both markets, whilst there are many competitors and a very small demand for this service amongst your costumers?
When I need insurances, I'll go to the best company in that market, which will not be a bank per se.