that's problematic for sure
though I once needed a union...and they were shit too. cared more about their own personal gigs.
Before any of these types of workers could organize and vote in a union we would first need to fix the laws which allow for union busting to be a thing. People in low skilled, easy to replace jobs like what you find in call centers who even breathe the word "union" just get fired and replaced. And if worse comes to worst the company will simply shut down the call center completely and open somewhere else or they'll simply outsource the work to Asia. Unions only work in jobs which require skill and training. If skilled workers hit the picket line the company can't function because they can't just hire people off the street if the job requires skill. But call center employees? Anyone who can fog a mirror has all the qualifications they'll ever need.self interest will always come into play. union members and leadership are not immune from the human condition.
and unions don't make sense in every instance (for example, if uber eats delivery drivers were to unionize they would have less money in pocket once they got through union dues and benefit plan costs, and would lose the independent contractor status that allows them to deduct fuel and (potentially) food expenses -- something Canadian bike couriers have known to take advantage of for years).
but fulfillment centre employees are pretty much the miners of the 21st century, should be paid a living wage (we know from costco the model can work) and should be unionizing if they aren't getting paid fairly.