And the union has an incentive to screw individual members. Given a situation where a company says it must either lower union benefits or go bust, the smart thing to do would be to preserve jobs by lowering benefits. But the union doesn't want to look "weak" in its negotiations with other companies, so it says no, the company goes under, and all of the union members at that company lose their jobs.
But the union stays in business, and continues to pay its officers wages commensurate with those paid by business management. If you are fortunate to work for the NEA, you can make as much as urban school administrators. The schools, of course, never go out of business.