Earlier quoted context omitted.
For the local national economy, an oligopoly seems possibly worse. On the international stage, it seems blindingly obvious that breaking up your local oligopoly to compete with larger foreign oligopolies or stated owned corporations is worse. Fundamentally, this is all about negotiating power, and the whole point of breaking up a monopoly/oligopoly is to reduce its negotiating power. But that's clearly a problem when…
Following your reasoning, we should just create and feed oligopolies to avoid, god help us, becoming "victims" of oligopolies from other countries... In other words, lets kill the competitiveness of the local economy, so that other countries won't be able to do just that. This is similar to the soldier who decides to commit suicide so that the foreign army won't have the chance to do so!
> we should just create and feed oligopolies to avoid, god help us, becoming "victims" of oligopolies from other countries...
This basically is exactly the strategy of China, at least with respect to international trade, and it's working absolutely wonderfully for them. In part, precisely because most of their competition is fragmented and paralyzed by infighting.