Newbie, the truth is, the mainstream airline life of new aircraft is getting ever shorter, with old buses needing lots of fettling being parked or shuttled off the godforsaken corners of the globe where labour is 50p/hour and the lives of the pax not valued much higher. Meanwhile our carriers prefer to bring in new aircraft and live off warranty and low initial servicing costs. And of course new aircraft are more reliable than ever before.
While you are right that the industry needs good engineers and there is many a maintenance manager bemoaning the shortage of supply they are an expensive resource, many companies can't or won't pay what it takes to get as many as they want and fewer still are prepared to put in the time and money to train them up. The shortages can't be that bad, then.
So at your end of the career ladder it's Catch-22 and not easy to get in. On the plus side once you are there you're in a good career. So get working at it, nobody's gonna make it happen for you, it's down to you. Good luck.