PUBG was directly inspired by H1Z1 is my point. Why is the line drawn there. Because PUBG eventually blew H1Z1 out the water. I guess that's kinda SOE's history. Everquest, H1Z1 both heavily inspired what would be titans and make their game more of a footnote, despite their popularity and success.
Well, gaming is evolution, that's why. Half-Life didn't invent FPS. Dark Souls didn't invent the soulslike formula. Metal Gear Solid was not the first third person game of the sort, neither was Tomb Raider. But despite these games taking cues from prior products, they became mainstream phenomena, and they were the ones who started inspiring future games. FPS games today aren't looking at Wolfenstein 3D thinking "that's what we wanna do, yeah". Devs who tried Battle Royale for the first time seeing the insane success of PUBG and Fortnite looked at those games to try and replicate the formula, they really didn't need to look up all the Minecraft mods or read the Battle Royale book by Koushun Takami to get the origins of it.