Unions won't help with any of those things. The decline of unions has been largely because folks have watched as the union shops have steadily gone out of business, replaced by cheaper overseas manufacturing. Rather than protecting the workers, their main success has been in accelerating the exodus of jobs out of the country.
It wasn't the unions that caused the outsourcing. It was simple economics. US manufacturing was exported whether or not the shop was union because even with today's too low minimum wage that cost is still higher than China which subsidizes the manufacturing businesses. You even noted the "cheaper overseas" part yourself. Unions had very little to do with that.
The fact of the matter is that the wealthy have the power, and the only thing that can balance that power is a strong central government with a strong desire to protect the workers. Things started declining under Reagan not because he broke the unions, but because he broke the government protection of workers at pretty much every level, *including* failing to defend unions. In the grand scheme of things, the decline of unions was below the noise floor.
Therein lies your problem. Most, if not all, of Congress are wealthy. Also most, if not all, have some sort of business they own outside of Congress or have large portfolios in the stock market. None of those are conducive to favor workers.
I come from WV where unions had their start in the coal mines. People have been killed fighting for their right to join a union here. For reference look up the battle of Blair Mountain or the history of Maitwan, WV. Interestingly enough, the coal company that owns that land proposed mountain top removal for it. Nothing like destroying not only nature but history for money!
As the Tennessee Ernie Ford song goes, "You load 16 tons what do you get? Another day older and deeper in debt."