By using the word 'industry' I mean all of the aviation sectors inclusively. The same would apply outside of aviation. Other industries would do well to significantly limit the reach of their associated union groups as well.
The problem with the your theory is that Businesses are just likely to operate as a union as the workers are which is where your argument falls apart. The AMA, The Pharmacy Guild, The AA4A, Business Council of Australia etc etc all influence decision making for their respective members, and in some cases actively prevent competition in certain markets acting just like union.
And given how weak Pilot Unions are I would argue that most Business Unions wield more power than the pilot unions.