You don't really need to engage with the process and its statistically proven to hurt fewer people.
They certainly succeed at protecting their industries when they can’t be replaced, but there really isn’t a remedy for an employer who is willing to not have a workforce.
As to what you are required to support...
No he didn't. He said the unions are obsolete, not the trades.
Then, once the job's done, you want that person off your payroll and out of your life. You don't care too much about the cost of labor, you just need it done right the first time. I can imagine a craft union being suitable for providing access to that kind of labor.
But driving cars and trucks around... yeah, no, that's a robot's job, sorry.
Also, without blacksmiths, where am I going to take my plate shield armor? I need it for ren faire.
Have a look on videos from Pakistan, India, Bangladesh or other part of south east Asia, where people are working in environment which can easily injure them or kill them. That's how European factories were looking like before unions have become to be a thing. Unions are direct consequence of greed of 19th century capitalists who refused to invest even bare minimum into safety and pay their workers properly while not working them to death.
This is the March of Dimes syndrome. Unions had noble goals at first, which they've fully accomplished (things like occupational safety rules are now the law for all employees, union or non-union), so they no longer have any useful purpose and their continued existence is now a net negative.
Like collective bargaining power for higher wages and benefits is net negative? I don't think so.
The negative aspects of unions in America are by legislative design, too. Laws have been passed to make unions work more poorly for workers and increase their unpopularity.