I agree on all of your points. If the majority supports unions (citations in my above comment), and everyone has the same vote (as you mention), it's just a matter of time of continuing organizing efforts while the folks who don't support it either exit the labor force [1] [2] or filter out of orgs attempting to organize who don't believe in it (younger workers with a longer labor participation time horizon). I fully admit there are lots of people who believe they're special, who have been or believe they will be lucky, ignore the data on the benefits of organizing, etc; you might never win them over. It's going to be a long slog, but wages and job security for the broad majority of people will not go up without it. Startup founders grind for delusions far more grandiose than this imho, so while I recognize being at the foot of a mountain on this topic in this specific socioeconomic system and point in time, I also don't think it's impossible.
And I really want to touch on your point about dues and unions. Workers should absolutely have high expectations for what their unions deliver, and should not tolerate any sort of drag, apathy, or lack of effort. With that said, it is another political process one must participate in, it isn't ordering an Uber. I have zero tolerance for union grift. Perhaps this calls for something like a non profit ratings agency, but for unions.
[1] https://charleshughsmith.blogspot.com/2022/08/are-older-work... ("In 2000, only 17.6% of the 55 and older populace had a job. Now the percentage is 37.5%. A 20% increase in the percentage of 55+ who are employed in a 20-year span is unprecedented. If the percentage of employed 55+ had stayed the same, there would only be 17 million 55+ workers today. Instead, there are over 37 million.") [2022]
[2] https://www.americanprogress.org/article/the-closing-gender-... ("Gen Zers are the most supportive of unions, with a mean approval rating of 64.3 compared with 60.5 for Millennials, 57.8 for Gen Xers, and 57.2 for Baby Boomers." [death and retirement rate is progress rate in this regard by age cohort; the faster the older cohort(s) who don't support organizing exit the workforce, this should potentially reduced the lift required to organize forward looking])
(demographics + culture + advocacy + time is my mental model on this, and I have arrived at this model from first principles, as a macro and demographics scholar)