Just making money even wouldn't be fair.
Once you make so much money you can buy laws to make yourself more money. (as you mentioned)
Once you have so much money you can buy competition before it becomes competition. (Look at how much of Microsoft's portfolio is actually acquisitions.) Their scale makes it infinitely easier to buy their reinvention (all while current legacy revenue still flows in as contracts end), and shift capital from a dying business to the future (like IBM buying Red Hat. Dell buying VMWare.)
Once you have so much market share, and you become a default part of all business (Outlook, Visa, ATT/Verizon, Google/Facebook ads) you become more of a tax on business. Companies either pay that necessary business tax, or they cant compete. Once institutions hit that "you need us to even exist, more than we need you as customers" level, their money multiplies itself. Obviously they can fade over time if they dont reinvent themselves (see above paragraph.)
Once billions are accrued into one place they tend to not just disappear.
These are market failures. Billionaires are becoming billionaires because of something not protecting against these feedback loops amplifying themselves ad infinitum.
There are often arguments that billionaire philanthropists and inventors spend their money better than governments. Tech giants do seem to have replaced the military and nasa in ways.
There may be a middle ground between "dont let billionaires buy influence and power, and collect riches, tax their wealth for equality" and "private industry is better than government." One of those middle grounds may be some kind of reimbursement or credit for contributions to society. Imagine a world where Facebook and Googles open source contribution values are quantified in a way that counts as charity. Another middle ground is public-private hybrids, where funding for research is public, research and profit for invention is private, and the output is publicly owned. Tax billionaires, and break up monopolies arent the only answers. They may be some answer, but they are reactive and dont address root causes of loops, and they dont actually create new creation systems to replace what they break apart.
One of the greatest market failures government power is capable of addressing is proprietary institutional silos. They should use their authority to incentivize consortium to implement open, federated, and decentralized standards, that any new market entrant can latch onto, benefit from, and improve. Whether those standards be payment networks, accounting system interoperability, communication, or data and infrastructure portability. Additionally, Government is equipped to incentivize long term value creation over short term wealth extraction. Absent of Government, companies seem to need to be either be private, or pseudo-private autocracies, where one or a few shareholders can stand firm and focus on the long game.
I don't know which is true, although I have suspicions, and unless you've revolutionized the discipline of economics (and decided to inform the world in Internet comments) your certainty is unwarranted. You could have at least acknowledged that counterarguments to your thesis exist.
Maybe you’re not understanding the concept of Rent Seeking and therefore don’t understand why it is detrimental to the economy as a whole.
There will never be a completely elimination if rent seeking as long ad humans are involved but it ahoulsnt be rewarded like it is
And yes, rent isn't value-creating. You created value when you well, created that capital which gives you rent. Value is the capital, not rent. Then yeah, you just sit on your ass and milk it, or just sell. Every capital is a monetary expression of the value of the unfair, rent-creating advantage you got. There's nothing wrong with that.
