Private Military Companies (PMCs) have been a thriving business for decades, and has substantially grown since the 2000s. There is now 10 military personnel for every 1 contractor. Their services are also highly varied. However, the west is going to learn nothing from this because Wagner is a not like traditional PMCs. Wagner's deep connection to the Russian apparatus makes them almost a para-military force, since the Russian government funds it – not just hires it. Interestingly, Wagner's major work isn't even in Ukraine or Syria, but in Africa. Few know how intensive Wagner operations in Africa currently are.
Saying that, I don't think PMCs are going to go away. Frankly, there is an overwhelming demand for PMCs, largely due to the kind of international conflicts that we have these days, how inter-connected our world is, and the inability of international law to move beyond 19th and 20th century mentality.
For example, many NGOs that operate in conflict zones are forced to hire PMCs for protection, as there isn't a realistic military or police force that would protect them – since, a lot of times NGOs work against the interest of the leadership of the country they service.
Sometimes it's just far more cost effective to hire a PMC to go fight a low-intensity insurgency that threatens major supply chains, than actually sending in military forces. And sometimes the rigidness of international law forces countries having to rely on PMCs which aren't beholden to standard rules.
I think the reality is that the world is largely decentralizing – to the exception of Ukraine and Russia, major conflicts between powerful nations is an incredible rarity. Fighting conventional wars are increasingly costly. But because the world is so inter-connected there is a large desire for nations to intervene in the affairs of others.
One of the biggest influences on my views on geopolitics came from reading books about how inter-connected trade plays an overwhelming role in shaping our world history. Books like The Silk Roads by Peter Frankopan, (There has been a sequen released a few years ago that I want to read). And 1177 B.C.: The Year Civilization Collapsed by Eric H. Cline, really solidified a view that so-so-so much of our international political affairs are tied directly to supply chains and economics. So many wars have been fought just to hold certain trade centers, many more over access to some of the smallest things taken for granted.
So in this context I think the necessity for more information based economies dependent on manufacturing economies functioning by a steady dependence on raw-goods from resource rich economies forces international intervention constantly.
An obvious: Russia, for all it's resource wealth in minerals, lumber, and energy, is utterly dependent on Europe for high-tech machinery and microprocessors, when that is cut off from them you can start seeing how rapidly they slow down in military production.
Simultaneously, a large chunk of the world is so utterly dependent on high quality micro processors that come from just a few countries: Taiwan, South, Korea, Japan, and the United States that the necessity of the US having to intervene in that part of the world is necessary for it's own survival.
In this environment, PMCs flourish. No American politician wants to have to go on public record telling his constituency their children have to go die in a war just so we can make sure that some dictator or petty warlord doesn't attempt to capture a massive monopoly on a rare earth minerals from an unstable African country no one ever heard of.