I can't think of a single unionized organization that is run as well as or better than union-free organizations. Unionized companies all seem to be crippled by bureaucracy and unable to improve performance and output.
Or how about Hollywood writers? The Writers Guild of America writers are responsible for most of the most successful movies and TV of the past decade or two (maybe longer). WGA writers are treated better than just about any other screenwriters around the world.
The PreK teacher at the local public school has been there over 10 years at the same school and has a masters degree. Union, of course.
I’m sure the public school system is more expensive overall. You get what you pay for.