To be fair, it's not merely that globalization has invalidated unions; to be frank, the conditions still exist for unions to wield considerable power, albeit diminished. While it's true that their negotiating leverage has been reduced by globalism, they still have way more of it than an individual worker; for this reason, it's been corporate sponsored policy across much of the country to actively attack and legislate unions out of existence and otherwise marginalize and undermine them, along with complicit politicos being given all the right bribes (sorry, campaign contributions) and lobbying to effect this.
There are solutions to this trend, with the most effective ones involving trade agreements that require meaningful minimum wage, environmental and labour standards to end the race to the bottom which has been responsible for so much of this disastrous outcome of neoliberal globalism, alongside global efforts to tackle tax evasion/avoidance, and local reaffirmation of unionization and tax fairness, mandatory E-Verify (and equivalents; if Trump were serious about stopping the illegals as opposed to a dog and pony show this would be one of his legislative priorities) to thwart the downward wage pressures exerted by illegals on the lower socioeconomic rungs, and the nullification of abusive labour outsourcing trends like work Visas.
Looks like we have some common ground. My wife worked for a big national union for over 30 years, as a health and pension plan manager. Aside from the health and pension plan, the union had little to offer it's members. OSHA has taken over the fight for safe working conditions, and other federal agencies have authority over labor practices. So it's not much of what unions do anymore. And they are trying to shift training programs over to community colleges to have taxpayers pay for apprenticeship training instead of the companies. (Right now, usually, a company sponsors an apprentice). That's why most unions oppose universal health care. My wife said to me many times the unions needed the health plans to retain members. Having said that, shortly after she retired the union turned over the entire health and welfare (pension) operation to a contracted non-union company and let go over 150 union (OPEIU) office workers, who made an average of about $50K per year to an operation paying non-union workers just over minimum wage. They said it was a "cost saving" move. I'm sure it was. Keep in mind this was a UNION doing this. To other union people.
I do agree that trade agreements need to be more balanced and fair to American based companies. But that ship has sailed. As illegal immigration resumes under Biden-Harris, and China resumes business as usual, you will see much more downward pressure on wages; except the highly skilled technicians that can keep the technology up and running. They will do fine.
All my grown kids have highly technical jobs that really can't be eliminated. My youngest son manages several dozen highly skilled IT people and it's database. He doesn't even look at college degrees anymore when he interviews. He looks at what the person can actually do. And the right person gets paid very well. My son says he pays so well because if he doesn't, somebody will steal them away....like he did.
The world....the entire globe...is becoming haves and have nots. Divided into two unequal camps by skill sets. Those with the right skill sets will do very, very well. Those who lack the skills, or who are just average, are a dime a dozen.
There is no government program that will change that.
I'd add one more thing. The way marriage has changed has a lot to do with income inequality. In the old days kids married much younger, before careers were established, and often the wife stayed home and raised the kids. More often than not, only one of the parents was real smart, and the intelligence of the kids was probably mixed a lot. Today, as I have seen with my own kids, they wait until careers are made and then marry another real smart person making very good money. And the kids usually turn out extra smart, and will get the best educations money can buy. My oldest son's wife is a lawyer. My daughter's husband is an airline pilot, and my youngest son's wife is a veterinarian. Smart kids are getting married later, to other smart kids. This trend does not bode well for future income equality.