That could be. However I think the language barrier is also a significant factor. But of course there is nothing inherently problematic about offshore developers.

I've had to deal with offshores my entire career and have even flown out to train them up. They are good people, but almost universally, they contract for U.S. companies via large body shops (you know who they are) that have awful pay, poor treatment of developers, and just a general culture of half-assing work. I've told various great offshore developers personally to leave as fast as possible and join literally any other organization for way more pay. Good developers have zero business working at those body shops that all the U.S. corps utilize.

Culture issues do exist. IME different cultures have very different approaches to communicating e.g. “I don’t know” or “I made a mistake”. Not everyone in a particular culture acts the same, but it definitely affects the average outcome.

It’s not a problem with individual offshore engineers. The problem is the way the business they are employed by operate.