I would rarely use it, but then I would try to pay for something with it and it would be declined, when I called they always said it was "suspended due to inactivity"

So for example, a backup card you use for gas only, or a store-branded Mastercard that you only usually use at that store.

You still run the risk of a block, but it's reduced.

In emergency you need to contact your bank.

I have had my card declined several times Once on travel to USA - I probably should have told them before - in this case I had to phone them an international call and it was immediately reinstated. They also denied a payment when it was in a place accross the country from my normal use, which wa good as it was not me trying to use it.

Basically if your spending is abnormal - e.g. in a different place or for a large amount then you might have to confirm the payment. The benefit is the bank is able to stop more fraud.