Because the current I485 processing time is around 41 months or just shy of 4 years. That card gives you to opportunity to work and travel in/out of the country while waiting for your green card.
I have worked at several employers (schools) that ignored qualified American citizens while claiming they could not find qualified people and tried to bring workers in on a H1 Vida or hire someone already here on a H1 Visa.
Is it legal to import someone on a H1 Visa while ignoring qualified American citizens who applied for the job?
Is it legal to hire someone already here on a H1 Visa while ignoring qualified American citizens who applied for the job?