The older I get, the more convinced I am that wealth disparity, either with individuals or corporations, is itself a root problem.
Consider a small community of 100 people all relatively equal in wealth/income; everyone’s got a job, and 10% of the community does residential construction. Anyone needs a house built, and these 10 people are able to build a reasonable sized one in 3-6 months for a reasonable price.
Let’s say that 3 of the people in this community get together and build a better mousetrap. The community is happy, they all start buying those mousetraps, and the 3 people are able to amass a bit of wealth. They choose to spend their wealth on big houses; each house takes 4 times as long to build but it’s 4 times as fancy. Problem is there’s only 10 people in residential construction, and they’re going to go where the money is, so they become experts in big houses. Now the people who want reasonable houses have to compete with the 3 wealthy people. Housing prices go up, more people get into construction to try and compensate, meaning other work doesn’t get done.
Is this good for anyone besides the 13 people who are either getting a big house, or getting paid better for building bigger houses? The answer is no, IMHO – the mere act of having that wealth means that those 3 people are able to adjust the societies priority in a way that benefits them but not society. If the people decide that the need a water filtration plant built, it’s going to be even more expensive because there’s a shortage of construction workers.
If we limit how much those 3 people (who maybe have formed a corporation) can amass in the first place, then maybe their houses are only 10% better instead of 400% better. The society’s ability to allocate labor is better aligned with the society’s needs as a whole.
All that to say, I don’t think there’s any benefit to letting any corporation amass society-altering wealth. Pin it to profits, pin it to assets, pin it to market share, whatever, but limiting the impact of corporations is a positive in its own right without worrying about specific anti-trust practices.
ETA: Or, what @Sitnam said in 1 sentence.