I think it's great that companies particularly large incumbents tend to decay and fall after a time. It promotes renewal and evolution, like the cycle of life and death. It's a bit sentimental to want a company to survive decades.
It would be much worse if the big incumbents all remained at the top and dug themselves into the regulators and politicians and crowded out others (they already do to a great extent but it could be a lot worse).
People in 1900, as consumers, thought they'd need a reliable supply of horse feed for the rest of their lives too.
Uncertainty and risk are big reasons why people fear change, I completely understand. I'm not saying the feeling or desire for stable incumbents is invalid, although maybe my comment could have been worded a bit better.
It would be much worse if the big incumbents all remained at the top and dug themselves into the regulators and politicians and crowded out others (they already do to a great extent but it could be a lot worse).