One problem is that so many companies are just subsidiaries held by holding companies that buy them to add to a portfolio or to maximize profitability and then flip them. A holding company isn't interested in long term growth, so the answer again is to take any profit and acquire smaller companies. Nobody builds factories anymore, they buy a company that already has the factory. So big companies become huge companies, and eventually they go public which makes it worse. In my professional career, the absolute worst thing to happen is a company going public because then the company has no owners with a personal connection to the company or its people. All history, loyalty, and time invested in employees and customers gets replaced by a nameless, faceless board of directors who only feel beholden to the stockholders. From that point forward the company lives and dies one quarter at a time, and every person below the executive level becomes a faceless cog in the machine. Bad quarter? Let go of 1,000 people to cut payroll and make the company look profitable. Two or three bad quarters? Combine that company with a sister company to hide the loss, and eventually sell it off or liquidate it.
Welcome to my world. My average lifespan at a company my entire adult life has been less than five years. I have been with my current company for ten (my longest ever) and during that ten years we have had three names and been held by two companies before being sold to the current parent company. Before that I was with a company you all know about, which is owned by a company you've never heard of. I have zero illusions about job security or company loyalty. They can call me in tomorrow and tell me thanks for the memories, and good luck. And you know what? That's the deal. I get paid for the work I do, until I don't. On the flip side, I will work hard for them until I decide to go somewhere else, and I won't offer them anything more than a hearty handshake and here's your computer back.