Everybody squeezes costs, including you and I. Don't you shop for the lowest prices? I do. Customers of fast food are pretty price sensitive.
In the case of the tech company...let's just say they are all but forgotten, while other players came along with competent management and have formed new multi-billion dollar businesses.
And, sure, there are a lot of incompetent employers. They usually go out of business. Businesses have a high failure rate, and it's pretty darn hard to make enough at it to put up with all the aggravation and work required to make it successful. Businessmen do not go into business to make a 3% return on capital, as anyone could buy a bond that pays 3%.
Bill Gates famously never went on vacation for something like the first two decades of Microsoft.
Back in high school I worked in fast food as a closer. One front end person, one backend person, one manager for dinner rush, late rush, clean up from the day both in the kitchen and the store, some basic prep for the next day (morning shift did main prep), and they kept pushing us to get our times down so that we could walk out the door as soon as the store closed rather than taking any time after closing for our cleanup, etc. Our labor cost per hour was likely around $17. The energy to run the ovens, refrigerators, etc was fairly consistent, while our labor cost for any extra time after closing was a variable cost that ate into their profit margin.
Doesn't matter what industry -- ask a doctor about their workload -- if management can squeeze labor costs, they will.