I can say that were ED to quit, I’d probably be looking to develop my own Longbow or Comanche 3/Gold clone. Not as extreme as what we have in DCS, but not as light as Ace Combat.
That’s because you have the big players behind Fortnite and Minecraft. Epic’s success with Fortnite has more to do with their raw market muscle (and Tencent money); likewise Minecraft having Microsoft’s backing – the same reason why MSFS2020 is going where it is.
PUBG, which might as well be Fortnite, was a tiny little thing that got lucky and went big. It’s not the norm and Fortnite could’ve easily fallen apart had anything been slightly different. Look at DayZ for another example here and that one fell apart real quick after the initial success.
Which easily could’ve flopped. Epic had to put a lot of money into it and there was no guarantee at the time that they’d get it back.
Honestly, even Fortnite, PUBG, whatever the latest craze is, all pale in comparison to the mobile game market. So if you want a steady money maker, look for gacha games on phones – low investment, low risk, high potential return.