The weird thing here is that if everything is social construct, then science as social construct is just as true as it would be as objective reality. Then you can just pick science as your favorite construct and call it a day.
But for some reason "social constructionist" seem to be often incredibly biased. Some things are "false" because they are constructs, but some things are "true" because they are constructs. And some things are just objectively horrible, while others are constructed as horrible.
Examples: rape culture is social construct, but mental distress from rape is suddenly not. Nationalism is "false" social construct, but Marxism is "true" social construct.