Everything has it's pros and cons.
poly is durable but can't be glued so the mechanical joints could leak, but the pipe can be curved when warm to achieve a large radius curve.
PVC is very common, rigid, glued joints are good but it can shatter if something happens since it's brittle compared to poly.
Flex PVC, glued joints and is the most flexible which will lessen the need for joints. Not as tough as poly or PVC for the most part. (But if you are going to smash each one with a hammer side by side, flex will win. A standard razor blade can cut flex but not poly or pvc)
Nothing is perfect, it has a lot to do with installation. I personally use all 3 but most often use flex, then some pvc, and then maybe some black on occasion. I've been noticing though that flex above ground does tend to get UV damage the quickest of all three. It can get brown and bubbly. This also might not be the clearest determination though as I've had PVC pipe and black poly pipe look normal and then shatter when attempting to cut them, the pipe had been sitting in the sun for many years.