Every company has their own way of doing things, their own software and their own product.
Even if you hire someone with a Ph.D you will not be able to drop and go.
And imported people need even more on the job training because they will need cultural training as well.
Your mentioned software. The IT/code/programmer crowd are just the latest casualties of the offshore/H1-B onslaught.
Twenty years ago, companies were shedding electrical, mechanical, computer, and most other engineers like you wouldn’t believe. Two years after NAFTA, and the WTO entry of china, and a degreed engineer was on par with a manager of a burger king.
The IT crowd are merely the latest victims of a global slave trade that been going on for at least the the last 20+ years. I’m actually surprised that all of the code/IT crowd lasted as long as they did.