>delta between company X profit and similar company Y's profit

If that were true then Amazon is doing terribly under Bezos.

Profits over time is an incomplete metric for measuring company success because CEOs can decide to invest it all back into capex.

That depends on how you calculate profit. Amazon has growing assets which is profit even if they don't pay taxes on their profit.

This is not limited to physical assets, if you do R&D and produce a valuable drug patent then you don't need to pay taxes on that value yet, but actual value was created.

Stock is at best a proxy for what you actually care about.

You're mixing concepts:

* Profits = Revenue - Expenses

* Assets + Liabilities = Equity

New asset purchases are expenses and not profits. Equity (total market cap) is an estimate of the value of the company, including assets and outstanding liabilities.

If you rent out a property for 30 years at same rate as your total expenses including mortgage payments then sell it after that point your profit is not actually zero for 30 years then the full value of the house on the final day. There are actually a lot of different ways you can record such a transaction each of which have different trade-offs.

This is also why asset depreciation is considered an expense. https://en.wikipedia.org/wiki/Depreciation However, it may also be recorded as income with the initial purchase being considered an expense.

PS: There are an insane number of useful ways to run your personal books, and a few legally required methods in various situations. But, IMO your goal should be match the underlying economic situation of your enterprise not simply move numbers around based on an abstract formula.

Assets - (External) Liabilities = Equity

How do you differentiate that from "all three CEOs are doing an exceptional job"?

Well it's by definition not exceptional if all comparably placed CEOs are performing the same. :) But, nitpick aside, I agree there's a flaw here, since it doesn't differentiate between the CEOs performing "to spec" or under spec. Though, when you get to have an agglomeration as big as a large multinational, there have to be serious missteps or moments of brilliance to really differentiate a bad and good CEO. Otherwise, it's hard to tease out the relationship between company performance and market share, entrenched employees, quality of invested capital, etc.

They would not be moving in lockstep.

Basically, companies are never actually identical so optimal moves for every company is going to be slightly different and this will compound over time. However, if each company is making the same moves then and getting the same results then none of them are making optimal choices.

Consider defense contractors may all be in the same market, but they have different contracts. Farms on the other hand are selling a commodity and are often mostly just at the whims of market forces.

It is much easier to compare companies that sell identical commodities.