It's partially due to fewer people wanting to work, which is caused by the laziness bred by becoming too successful and the inevitable failures of a society that enforces altruism, and destroying it's homogeneity through diversity, but it's also because these corporations are lying through their teeth. I'd bet that most of the big corporations are allied with the same globalists that are pushing diversity, multiculturalism, and mass non-white immigration into every white country on the planet, in every sector of society.

For example, I used to work at Arkins Park Stone for a few years, a sandstone rock quarry in Colorado. They employed a lot of Mexican immigrants, and the execs and top managers always claimed they couldn't get help from local white people, claiming "they don't want to do this work". However, one of the office guys told me once that it was a complete lie. Legally, to get workers from Mexico, they have to run help wanted ads, and whenever they do they get tons of applications from people who want to work, but they throw all of those applications in the trash, claiming "we got no applicants", and then bring in the Mexican laborers through work visas. The only reason they do this is because the Mexicans work for much lower wages. The only white guys they let in are the ones that work in the saw shop and run the heavy equipment, which requires higher intelligence so you don't fuck up millions of dollars worth of equipment.