Most of the time with trade jobs you have to know somebody to get them because the people hiring already know somebody they would like to hire. Or you have to be on the small job hunting sites like kijiji at 10 pm because that's when the small companies have a chance to put their ad up. Location matters too, good luck getting apprenticeships in certain parts of the country. Most of the people I know are in work like this and it's really not the sunshine and rainbows people try to make it out as.
Well, that's kinda the point, though, isn't it? If you don't have a degree from Yale that vouches for your electronics expertise, well someone is going to need to vouch for you... and that someone will be somebody already in the union. That's pretty much why they work. People know each other. They work with each other. They tell you honestly whether dude is right for X, Y, or Z job. Or if he isn't. So the part about "knowing someone, so you can get in" is just how life was before colleges came around and began passing out "entry tickets" for $35k a piece. You had to know someone, and that someone had to vouch for you. "Take a chance on this kid. He's dumb now, but he learns fast, and works hard."
Really? I'm not sure I follow. To get a job you generally need someone to vouch for you. A friend introduces you to his Union boss, or a university gives you a piece of paper. Either way, that's your entry ticket to the job market. Unless you just go out totally on your own and build something new that every just must have. But those types of ideas and people are rare, indeed.