If your union has no teeth, it doesn't. I keep hearing about Starbucks unionizing. A coffee shop with primarily part-time workers. I also work in unionized retail. What does unionized retail do for the part-timer? What does my union do? Makes sure everyone gets equal hours and the hard workers can't consistently work extra hours to pay their bills. Those same hard-workers also have to work with people who barely do any work at all, because once they pass their 3 months they can't be fired thanks to the union. What does unionized retail do for the full-timer (if you're lucky enough to get one of the few full-time positions)? Pays them slightly more than the part-timers and gives them 40 hours per week, but doesn't pay them enough to pay their bills. Bills that will have likely increased while you waited 1-2 years for a full-time position to become available, and went into debt working as a part-timer. Oh and if you didn't get in immediately on day 1 of the store opening? No full-time position for you. It goes by seniority date.
People on this sub want Walmart to unionize. Do you know what happens if Walmart unionizes? The “part timers” who get 40+ hours per week every week will now be getting 10 hours per week, and the people who get 0 hours per week because they don't do any work (and managers only schedule them when they are desperate)…. Will also now be getting 10 hours per week, and won't be able to be fired. Unions completely screw over part-timers in retail, and do the bare minimum to take care of their full-timers. Unions don't solve all the problems. I don't live in the USA so maybe the health insurance thing would be huge, so I can't comment on that.
I'm not anti-union. But if you work for a place that is primarily staffed by part-time workers, the union is not going to help you. It is going to exploit you to take care of its full-time workers. And it's only going to negotiate the bare minimum for the full-time workers, it's not actually going to be a livable wage like it was 10, 20, or 30 years ago (and yes, they did used to negotiate a livable wage – it's right in my union contract, “people hired before X date make Y per hour” which is way more than what I make). And if you manage to get one of those few full-time positions and stay with the company for more than a decade, they will exploit the people who are hired after you. A new contract will be drafted. “People hired after X date make less money than you do.” You vote yes to the contract because they're not touching your wages. But that exploitative contract only exists because your union has no teeth and doesn't care to negotiate something better for everyone. Years down the line your company (and your union) are a shell of their former selves.
The whole system needs to be reformed. Unions might be part of the answer, but they are not the answer. Many people work unionized jobs and still make no money and suffer every day, just like their non-union counterparts.