> If you (as a country) insist on competition and absence of mega corps in your country while a country next to you subsidizes mega corps that outcompete your smaller companies - you will lose.
The assumption here is that megacorps are a competitive advantage. Let's look at a counterexample.
Suppose solar manufacturing is a growth industry. China wants to dominate it, so they subsidize it. Is there now a single megacorp in China that makes all the solar panels? No, it's a competitive industry there, but because of the subsidies that industry outcompetes the industries in other countries, with the result that China as a whole makes 80% of the world's solar panels. Others can't compete because of the subsidies, not because of a monopolist. Or, after the subsidies have existed for long enough, because the whole supply chain ends up in that country and other countries don't have the local knowledge or infrastructure to even do it anymore. So that kind of subsidization is a problem, but it's a different problem and "you need your own megacorps" is no solution.
Now let's go back to Oracle. How is it that they make so much money? The premise of copyright is you get a temporary monopoly in exchange for creating something and that allows you to recover your costs. Originally this was 14 years; it's not so temporary anymore. Also, the premise was that you sell a copy and get money and then if you want more money you need to create more works.
How does Oracle actually work? They don't sell you a copy, they sell you a license. The law allowing this was a choice, and a bad one. Having a monopoly isn't illegal under the antitrust laws; abusing one is. But doing that with the copyright monopoly is largely ignored, which is what license terms more restrictive than the copyright statue do. So instead of buying some database software for a one-time fee and then being able to use it as long as you're satisfied with that version of it, you get a temporary license that expires if you stop paying a recurring fee. Meanwhile your data is now in a proprietary database with high costs to extricate it, so you're locked in.
Is Oracle then out-competing all of their smaller competitors? Not really. Tons of people use Postgres or MariaDB or SQLite, and there are several other proprietary databases as well. But Oracle still gets to stick it to all the organizations that are locked in to Oracle, because the industry lobbied for laws that allow them to.
And then you also see Oracle sticking it to organizations in e.g. Europe. Is that because Oracle's size allows them to outcompete smaller companies this time? No, the same competitors are still there, it's because Europe has similar laws that allow the company screw their customers in similar ways, instead of limiting copyright to the selling of copies.
By contrast, if you look at something like Visa and Mastercard, that's a major duopoly in the US. And those cards are accepted in many other countries, but they often have competitors there, when those countries have laws that facilitate competition. Because the companies get big by laws that thwart competition, but when that's their advantage, the advantage doesn't stick where those laws don't exist. If anything it puts them at a disadvantage because being insulated from competitive pressure domestically makes them unresponsive and inefficient.
Which is why corporations are always lobbying to have the laws that prop up their concentrated markets enshrined into international treaties.
> Somebody will rule
This is the assumption most in need of being challenged. "There must be a king" is a fallacy. There will either be a king, or there will be a population of people dedicated to preventing anyone from establishing a throne.
The latter is what you get from a system of well-devised checks and balances, one of which is competitive markets. Emphasis on competitive.