I have seen people at AT&T on H1B visas who, in my view, should not have been given those roles. Qualified American workers could have filled them just as well. There is a real problem at AT&T, plus a manufactured one. Upper management often says they cannot find qualified candidates for certain positions, which I believe is misleading. The real motivation seems to be securing cheaper labor.
I have also noticed a recurring pattern in tech. Once companies start offshoring jobs, especially in development, that shift tends to trigger greater use of H1B visas. This happens because they have no intention of investing in training American workers. I say this based on experience at a Fortune 10 company. These firms are not short on cash, they simply choose not to pay American employees what they are worth.