[hellosailor]

Jotun-
Well, size is size.

Regardless of the material, you need a strainer adequate for the engine cooling needs, and some extra capacity since the strainer usually is ignored and gets some growth in it from time to time.

Proper installation in tight spaces, which attaches the strainer to the hull or bulkhead so it can't tug on the hoses, yet leaves room to access the bowl for easy cleaning, can become a much larger project. And as K1 points out, the strainer should also be located so it can't be damaged by things (or feet) tossing about.

Regardless of the material.

Personally I've never seen a plastic strainer that looked flimsy enough for engine suction to collapse it. I'd expect the rubber fins in the impeller pump to flop about and the suction to fail, or the hose collapse, first. But sooner or later, someone will probably bring a $1.79 made-in-china strainer on the market, flimsy enough to collapse in just that way. Oooh, wait, that's an idea, a disposable strainer, just the thing for those dainty folks who don't want to clean the real one out every once in a while!