Why not let big companies die and be replaced by startups if the only way they can succeed is by [ab]using their incumbent position to “rejuvenate” (a euphemism

Why not let big companies die and be replaced by startups if the only way they can succeed is by [ab]using their incumbent position to “rejuvenate” (a euphemism if ever I saw one!)? It would stop worse products winning as a result of resources gained through prior successes (and monopolistic practices). In fact, I’d be happy to see a situation where sufficiently unrelated businesses have to be sold off after some grace period even if they were developed in house.