When you have industrial machines and all the attachments necessary for the job, along with doing the same thing over and over, you get pretty fast and pretty good.
My mom had a dress manufacturing business in New York when I was a kid, and that is how I learned to sew - on an industrial machine. As an adult, when I started quilting and bought a domestic machine, it was like UGH - this is so slow!! :-) She still has an old Singer industrial machine that weighs a ton in her bedroopm, and I asked her if I could have it when she no longer sews on it. That time is getting pretty close, unfortunately, mom is 91 and rarely sews anymore.