My counter to your counter is that the MCU is no longer set up as a series of self contained movies. Each movie sets up a piece and continues the grander "MCU".
When a film noir movie occurs, it operates under the rules of film noir....which is fine. But all of these movies operate in the same scope, with a "quasi realistic earth". Aka some measure of logic is meant to be applied.
In one film we establish that a group of super heroes will unite to face a large threat. Then in the next movie, against a threat that is equal or even greater than the previous one, no one makes a phone call. In a series of individual movies that are intended to be completely stand alone, I can respect that.... but not in an MCU where other characters are literally referenced by name. These people know the other people exist, heck are often colleagues with them. So the idea that these relatively smart people wouldn't make the very logical and smart call to bring in some big players when the world is about to blow up.... that just really strains credibility.
The same thing with the celestials. Its established that the celestials have a plan that can be comprehended, at the end of the day its a pretty simple plot.... grow a new celestial by absorbing all the people on a planet. So the celestial seems to act in a reasonably logical way. So again this makes the extremely illogical decisions just that much more obvious. If they had gone with "the celestials are just inscrutible in their logic and ways"....ok, that works for me, I can respect that ungodly powerful and utterly alien beings wouldn't have any thought process like my own.
Now again I can strain my disbelief, but the movie keeps hammering it in. For example, I could think "okay they are machines, but they kind of grow in their own unique and special ways which is why they are all different, like a baller fractal pattern". Except then the movie tells me "we built the eternals to have no deviation and be just exactly what we want"... which tosses my rationalizations out the window. The movie on the one hand tells me Eternals are cookie cutter....but then gives me a diverse and unique cast because......because?
Now the Eternals is certainly not the only MCU movie that has this problem, and plenty of nonMCU movies have this issue as well. But ultimately for me in part its the enjoyment factor. When I am super engrossed in a movie, I ignore the nitpicks. When I'm sitting in my chair kind of bored....nitpicks is all I can think about. For example the new Spiderman has plenty of actual issues when you dig into it....but I don't care, it was fun, thoughtful, emotional, and a great ride....so I ignored those things and moved on. Eternals for me just moved a bit too slowly.
