I spent most of my working life as a government employee. It is ironic as my degrees were all in business and I taught business management, although I only worked in the private sector for a couple of years.
I have worked for county government, the federal government (two branches), a community college district, three state governments, and one territory - Guam. All but four years of that was as a teacher or professor. Although at times I was represented by a union, I never joined one.
The elaborate panoply of employee protections most civil servants enjoy constitute protection enough from employer predation. Add to that the facts that governments essentially never go bankrupt nor do they experience M & A activity that threatens job security.
For those reasons, I am firmly of the opinion that government employees should not be able to form unions, bargain collectively with their government employer, and strike. Teachers unions - the National Education Association and the American Federation of Teachers - are particularly glaring examples of why public employees should not be unionized.
As presently constituted, many of the public schools of this country exist primarily for the benefit of the teachers, administrators, and staff. The poor test scores of their student results make this emphasis clear.
The teacher unions fight tooth and nail against efforts to give parents alternatives to the public schools - charter schools, private schools, and home schooling. They've got what is almost a monopoly and don't want any competition.