I bought a Square Trade extended warranty on Amazon and it was limited to the value of the phone. That probably reduces it to a one claim policy.
The cost was a fifth of the phone's price. Smart phones have a non-accidental failure rate much less than one in twenty - with some models its as low as one in fifty. Many of those claims are covered within the statutory guarantee period and standard consumer protection or home contents insurance (provided the excess is low). Assuming half the failures are covered by consumer law, then without extended warranty you could expect to buy a replacement for no more than one in every forty phones you own. Whereas the warranty charges for one in every five. So far a no-brainer.
However my policy includes accidental damage. " ..accidents covered include drops, spills and liquid damage associated with the handling and use of the insured item. It does not provide protection against theft, loss, reckless or abusive conduct, cosmetic damage, damage... " It also does not cover the impact of weather.
The value of this cover then depends on your personal care and usage (drops and water damage is a major cause of accidental loss), and how effective a claims service is provided - of which I have no experience.
There are other levels of cover so you pays your money and make your choice.
