Starting from the current state of affairs in the world
, this is extremely unlikely. The major impetus behind the formation of any state is mutual defense. Having a lot of money doesn't mean anything if you cannot prevent some other guy taking it from you. US defense spending is ~600 billion USD yearly. Apple's most recent net income (before paying shareholders, etc) is ~45 billion USD. The US military recruits from a population of 320M; how many able bodied people will live in the Apple Republic? How do they maintain deterrence against WMDs? So , you need at least a combination of the following to become true:
* Warfare is conducted largely by AI (No need for a large population)
* Your corporations become at least 5-times richer than the richest corporations of our era (Corporations can afford standing militaries)
* The world becomes a much more peaceful place.
* Either WMDs are somehow eliminated, or the world is fine with extreme proliferation of them (Apple has its own nuclear arsenal, etc).
2 and 3 may be contradictory. If income inequality continues to rise, it is extremely unlikely that violence would decline.
The second issue that these tropes always ignore is the granularity of the corporate world.
Look at a list of corporations by revenue. You will notice two things:
1. The list changes every quarter
2. There is very little difference between any two corporations listed one after the other, in term of revenue. For example, in the most current list #43 and #44 have ~107B USD in revenue.
So, how thinly are we going to slice the ham? How many independent corporation territories are we looking at? Where do you draw the line in terms of revenue? How about the very next corporation on the list?
Secondly, although the major corporations are separate entities in terms of operations, the ownership is very much overlapping. Except for Chinese state owned "corporations" and a few family owned ones, great majority of these corporations are publicly traded, so who owns the corporation literally changes by the minute. Also, it is not uncommon for wealthy individuals and investment funds to hold major positions on the boards of several corporations. If I am sitting on the board of Apple, Shell, and McKesson, do I become a citizen of Apple Rebublic, or Shell rebublic, or McKesson republic?
Therefore, you need a combination of the following, also:
* Major mergers result in mega conglomerates in a scale unheard of before. 207
(Historically, over-expanded corporations have not been very profitable. Also, you would need to defeat antitrust legislation somehow.)
* Relatively small number of individuals somehow gain control of these conglomerates (seems very unlikely starting from today's world).
Corporations progressively take control over social matters in their headquartes and small surrounding territories, providing employment, security, education, health, roads, transportation and a long etc
How this could be profitable for a corporation is hard to imagine. A corporate HQ is just an office building. Apple does not design, manufacture, and ship all its products from one HQ. It owns assets around the world. Also, corporate HQs are already in cities with very decent transportation, healthcare, and education. So, you also need the following, which seems contradictory to your second requirement ("stable").
* The state and local governments become so dysfunctional that the country's infrastructure is actually crumbling. Major centers of learning (Harvard, Stanford, etc) somehow collapse. (Only then, it may perhaps be profitable for the corporations to finance schools, roads, etc).
like issuing passports, managing their own international relations and stablishing a judiciary.
Running the judiciary inside their micro-state is of little use to the corporation. What judiciary will they turn to for conflicts with other corporations? What do nation-states do when they have conflict? There is no court with enforceable jurisdiction over all nation states. They either resort to long diplomatic process or duke it out on the battlefield. Not very profitable... So you also need:
* The definition of a corporation changes from a for profit entity to something else. (Perhaps, instead of sovereignty, the corporations make sponsorship agreements with existing nation-states, the United States of Apple, The United Kingdom of Shell, England, and Northern Ireland, etc) 207