It works something like insurance, its only worth it if you need it. Otherwise its a piece of mind thing. Statistically, if they made financial sense for the consumer, FCA would not be selling them (they wouldn't be making money). So most everyone won't get much benefit beside a rental car.
Financial advisers used to tell you to put the warranty cost into a savings account and in the long run you would be better off. Those were the times where a shade tree mechanic could diagnose and repair most problems and extended warranties did not make much, if any, sense. But these days repairing a vehicle can cost real money. If you are that unlucky one with thousands of repair bills, the warranty is of great benefit.
It seems like, today, any simple thing needs a hook up to the dealer test set to diagnose and reprogram. One can quickly spend a lot of money repairing a fully option vehicle. What does a compressor or airlift bag cost to repair now days? Seems like a replacement radio is over a grand now. So the risk is that if something breaks it has potentially significant expense that the extended warranty would help mitigate. For the vast majority, nothing will break during the warranty period, so its a waste of money.
I noticed that the cost of extended warranties has gone up quite a bit over the past few years. So it comes down to "do you feel lucky" and how uncomfortable you are with risk?