With Covenant's release, the mythology makes even less sense than ever. The original 4 all had different writers and directors and as such pretty significant behaviors between individual xenomorphs and the overall lifecycle of the species. Ridley returns with Prometheus and introduces a hitherto unknown background to the species that involves the creators of humanity (and I guess ALL live on Earth (and maybe the universe?)) and some magical black goo that is both a biological weapon and a creation tool, and has different properties pretty much in any given situation.
Remove yourself from all the weird Biblical nonsense and Covenant essentially reveals that the overarching big bad of the series is not Weyland-Yutani, but a rogue bad robot who was created by Mr. Weyland but pretty much instantly hated humans because...idk, he just instantly had a distaste for his creators even before Weyland bossed him around. He's disillusioned with not only his creators, but his creators' creators, so he breaks programing and decides to experiment with creating his own species that can kill both, eventually ending up with the xenomorph as the "perfect organism". Spending 10 years alone experimenting with how to create a xenomorph with every possible species on the Engineer planet, he eventually decided on weird alien wasps as the main basis of embryos, which I guess explains the queen and hive mentality seen in Aliens-Resurrection.
Prometheus and Covenant imply that David created the xenomorph species both unintentionally (in Prometheus) and intentionally (Covenant), neither of which line up with Alien-Resurrection. There's also all the little things, like the Prometheus and Covenant ships being ABSURDLY more advanced than the Nostromo, to the degree of a company in 2017 using MSDOS. I get that the Nostromo was basically a trucker ship, but imagine seeing a semi from the 1970s on the road in 2017, and even that seems absurd in comparison to the technological differences between Prometheus/Covenant and Nostromo.
So we're left with a few options. Either the xenomorph (or its variations, at least) is a naturally occurring species, the Engineers created both humanity and xenos, or David created the xenos. This is not taking into account that, if David created the "perfect organism" by Covenant, that the life cycle becomes more complicated and worse as the series goes on chronologically. A facehugger in Covenant can implant within seconds, while it needs a significant amount of time to do so in the rest of the movies. The chestbursters in Covenant are full on tiny xenos that can grow to full sized almost immediately without killing/eating to gain mass. Meanwhile, 20 years later, they are larvae that pop out not fully developed and need to consume to grow. It makes no sense to me that the perfect organism would become LESS evolved over the years.
So, is there any way to save the series?