Sure, the killers vs achievers scheme matters a lot, allowing two kinds of players enjoy the game at the same time. But nothing explains this success. After all, the basic gameplay is FPS, shooting other people, which was implemented zillion times and much-much better than bug-ridden PUBG.
I believe its success has a lot to do with widespread rigging and P2W. Players are tired that their skill or even effort means nothing next to their credit card (either used above or below the table). That devs, either as a company, or as corrupt individuals skew the table.
How is PUBG different? Is the company and its devs are saints? Far from it. They sell lootboxes which are totally cosmetic (I’m sure that if you spend a bigger sum, the circle centers on you for a few games), and they openly declare streamers above the law.
But the PUBG game design is inherently unfair, which is refreshing compared to the “we are totally fair game” schemes. It’s 1v99. Everyone on the map is your enemy. Everything tries to kill you. Losing 1v99 is much less frustrating than losing a totally fair game. Winning 1v99 is much more rewarding than winning a fair 1v1. Also, the autoaim cheaters, dev’s friends and crate buyers are not necessarily killing you. They are also killing each other, giving you a chance to climb high.
A game of open chance, where circle placement heavily influences the outcome, where random loot can decide if you are fully decked after a house or have nothing but a pump-action shotgun after 10 is better than one where you expect fairness but there is none. PUBG success is the symptom of the frustration with lack of game fairness. The abandonment of the hope of fair 1v1 and embracing 1v99 instead.
I’m sure that the next runaway success won’t be some new design, it will be simply an old design, with a binding contract, with data transparency and third party audits to create a game which isn’t “better” than the ones on the market, merely not a scam.