You don’t lower your prices on the off chance a competitor might enter the market in the future. You wait until they have invested capital but before they start making profits and are at their most vulnerable.
So if that's the expected outcome, it might be better to prevent competitors from building factories in the first place.
A similar thing happened in the railway world, where two state owned railway companies colluded to have used rail cars scrapped so that their privately owned competitors can't buy them: https://www.railway-technology.com/news/ec-cd-obb-antitrust-...