I'm even struggling to come up with counter examples where a major established company is able to successfully pivot when the business model that brought them success is no long as viable as it once was. Maybe IBM counts in that they still exist, although I'd argue they aren't nearly the omnipresent force they were back in the day. You could also count widely diversified companies, but I probably wouldn't because they never really have to try to pivot the entire business.

As you said, finding a balance is hard and maybe not truly possible.