I agree with most people here that good bananas are the way to go. You can often slightly spread out the banana & make it fit quite tightly & it will never come out unless you want it to.
I think the primary reason spades come loose, especially with thicker speaker wires, is that inherently, the wire often must make an immediate or pretty quick 90 degree turn to accommodate where it’s going especially on the amp end. This can put pressure on the connection & eventually loosen. Thus depending upon the application & the specific equipment involved, they can be the wrong choice.

