Think of the kinds of people who vie for leadership roles at established companies like Sears was at the time. Those people aren't innovators and creators. They're management types, MBAs, bureaucrats.
And fair enough: When the ship is that big and there are that many people on board, you often don't want to "move fast and break things," because the downstream effects can be extreme. Now you've just broken a company that had been working for decades. You're incentivized to take small risks with high likelihoods of reward.
Of course, the problem is, at some point that becomes fatal. A balance can be struck, but it can be hard when the original driving force is long gone.
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.
Sony is perhaps a good example. Most of the product categories that they became known for, like radios, cassette players, analog TVs and VCRs, are gone, replaced by PCs, smartphones, Playstation and their media empire and industrial products like CMOS sensors that are everywhere. They've seen multiple times a major business segment sink beneath their feet, and survived.
Apple: suffered from Windows PC competition in the 1990s but came roaring back under Steve Jobs. They doubled down on high-quality design, user experience, and vertical integration, and even switched from PowerPC to x86 and ARM, and from classic macOS to BSD-based OS X.
HP(E): after stumbling with itanium, replaced its proprietary Unix server business with x86 and Linux.
And fair enough: When the ship is that big and there are that many people on board, you often don't want to "move fast and break things," because the downstream effects can be extreme. Now you've just broken a company that had been working for decades. You're incentivized to take small risks with high likelihoods of reward.
Of course, the problem is, at some point that becomes fatal. A balance can be struck, but it can be hard when the original driving force is long gone.