I’m not even sure there’s a counterfactual world where GE is a $m trillion business: The global economy has largely evolved beyond these massive, diverse conglomerates, and likely all to the good.
What does a “wow, GE really has been managed wonderfully since 1980” story even look like? I imagine they split up much earlier, each spinoff establishes their own brand, and there’s no “GE” to talk about.
It's not likely to pop 800% tomorrow, but it's more likely to produce reliable long-term value because it's pre-diversified.
For some reason, the Asian kerietsu/chaebol conglomerates seem to be able to handle it well. Nobody would deny Hyundai or Sony being hugely successful as conglomerates.