I've come to embrace this as the business lifecycle. It's quite well-studied. Eventually, all businesses rest on their laurels; over-price, under-compete, and allow space for newer entrants. If we consider the positives here, this creates fantastic market and product dynamism, and (in theory) prevents companies becoming country-sized monopolies. I'm actually more concerned about companies which remain competitive and loved over generations. The kind of global power they could wield is scary.