Yes, it is significantly harder to fire someone in Germany compared to "at-will" employment in places like the U.S. German labor laws heavily favor the employee, requiring valid legal reasons and a strict formal process to avoid litigation or fines.
Right to work laws originated with the passage of the federal Taft-Hartley Act in 1947, which granted individual states the authority to outlaw mandatory union membership or fee payments as a condition of employment.
Michigan became right to work in 2012. Republican governor Rick Snyder.
This didn't all just happen in 1978. It just started happening then. Actually it looks like it started in 1947. Slowly but surely, we have moved towards where we are now. Most middle class Americans aren't saving enough to retire at 65. Not like back in the good old days. Back then 35% of our workforce was unionized. We had big fat thriving middle class the world had never seen before.
GM was our largest employer. Today it's Walmart.
This is why I say they aren't "American" companies. They don't care about anything other than profits. If the car might kill you, they weigh the cost of recalling vs. paying you because the defect killed your baby or mom or sister. If it pollutes, they don't want to pay for clean air. If it's cheaper to have it made in China, do it.
Government can either allow or not allow them. Trump would allow. Biden/Kamala would not.