Simple Argument for why Unions for public workers are necessary

When you have a group of 5000 or more people trying to negotiate with 200 or fewer employers, like in the government sector, it will be impossible for 5000 people to negotiate with 200 without a representative from the masses. Also, my Dad works in the public sector and where one of my uncles who does the same type of job (programming) can afford to go on family trips to California every few years while one trip for one of us is an extremely expensive undertaking. Without unions, thousands of workers with the same status all under one employer would never be able to negotiate. Unions are much more effective for the employer too in fact. Instead of having to deal with each employer at once they just talk to the union's elected president, elected for their speaking skills, leadership, and negotiating skills, which improves the time of the employer and the standard of living for the workers. This is why unions are necessary in the public sector, without them there would be no dialogue between the workers and employers which is an extremely unstable model because the negotiation is then replaced with strikes.