my point of contention is that One plays with the creator god Primus stuff too. If they were just thirteen ancient rulers or something, it wouldn’t be so jarring and unceremonious
I get what TFO is going for, and the story it tells is basic but it works... it also keeps Optimus grounded because sure he's been selected by Robot God to be Bestest Boy, but so was Zeta and Zeta still got punk'd out. So Optimus being chosen as Prime doesn't mean he's an invisible god warrior. Which adds to the drama for upcoming stories as the War with the Decepticons expands (you know... in an alternate universe where there were upcoming stories

).
But it does create a bit of a disconnect where these thirteen divinely appointed warriors and leaders (and the movie leaves no ambiguity about Primus being a genuine divine force) all got taken out by their sassy secretary, his goth gf, and their squid army. Someone here (may have even been you) said it makes them come off less like the Olympians of Greek myth and more like the '90s Bulls.
It's the major pitfall of TFO's decision to not make Megatronus evil. It makes the Thirteen a united front, which should mean they're unstoppable, but again... not so much.
The story of Liege's manipulation and Megatronus' betrayal may be a bit cliched, but it does work to explain how the thirteen chosen children of Primus wielding the weapons of Robot God himself could fall. The only way they could fall, from within, is what happened. It allows the Thirteen to remain all powerful and awe-inspiring while giving a narratively satisfying answer as to how a group like that vanished.
TFO tries to reinvent the whole narrative, and in some ways it's compelling, but it does leave the Thirteen looking a wee bit s**t.