Combat as War is about 1) composition of encounters being based on simulationist realism (as opposed to being based on game balance as it is in the opposed school of thought, Combat as Sport); 2) not fudging the dice. Although I could be mistaken about #2.
While people avoiding things that they can't steamroll is one logical response to that scenario, it certainly is neither a) inherent to it, nor b) the only possible outcome.
In Combat as Sport, you are very limited to a very narrow range of acceptable encounter difficulty. In Combat as War, you have absolutely no such limitation, and encounters organically span the entire spectrum of difficulties, with a correspondingly broad range of outcomes. Claiming that CaW encounter difficulty levels / outcomes are somehow confined to certain narrow range(s) is hilariously missing the mark.
I've had GMs in tournament run modules that were not neutral. They clearly wanted someone to win / someone to lose. Otoh, I've known plenty of people who could deliver a neutral interpretation of the rules as one of the players. So, in practice, the line for accuracy and neutrality isn't where you are describing it to be.
That having been said, one would hope that anyone empowered to make a ruling was someone who cares about the game being fun. Thus, I claim that the only people worth empowering to make rulings are those who are not impartial.
Which seems to largely match much of your ideas about the GM being a fan of the PCs.
That having been said, I personally still prefer impartial rulings.
Um, no. The best part of the difference between TTRPGs and CRPG is the ability of the human GM to go off script in a TTRPGs. Having a nice, static start condition can be of benefit to both. If the party wants to take Tomb of Horrors and have their skeleton army strip mine the hill, they can do so in a TTRPG. Same static map, same objective, different approach.
Or, the group can change the objective, and recruit the locals, and/or get rich looting the corpses of dead adventurers who fail the test. All without changing the start conditions.
And, yes, the GM could change the start conditions if for some reason the module didn't fit their world. Say, for example, it's been established that the PCs have already made the entire world flat, so there can't possibly be an ancient hill left. But having to make square pegs fit in round holes is hardly the best part of TTRPGs.
You've gotta look at the big picture.
I was just talking to friends about our haunted house experience. They said that, while, this year, they were less scared and therefore got to enjoy the haunted house more in the moment, looking back on it, it was a better overall experience last year, when they were more scared and having less fun in the moment.
Changing the holy module, you lose out on the experience that is the module. I've lost count of the number of times I've tried to talk to people about their experience with a module, only to discover that we lack common ground, because the GMs had changed things for one or both of us. Or run through a module, only to read it later and discover that the GM changed it in a way that made it worse.
I've played at tables where all new characters start at first level, with no catchup mechanics. And it worked fine. You don't have to have the ability to catch up to have fun. Balance is not a synonym for fun.
And I've even seen exactly the scenario you describe, but in an online game. In this scenario, what the old timers had that was taken away was the only thing I cared about in the game, so both that solution or your solution would represent a total failure, to me.
There are lots of possible solutions to the "problem" you describe. That the GMs failed to select one that worked for you does not logically mean that that entire class of implementations is devoid of merit.
Ok, I agree with tailor making hooks for characters (or, alternately, tailor making / choosing characters for pre-made hooks). And, while not my preference, I can agree with tailoring an encounter for someone who isn't getting enough time in the spotlight.
But I believe you've conflated tier and spotlight time, or tier and power. My signature tier 1 wizard, Quertus, for whom this account is named, generally plays second fiddle to characters like the party Fighter and Monk.
So, out of morbid curiosity, what would you do to custom tailor a game to Quertus' party, or one like it, where the tier 1 Wizard is most likely to get voted off the island?
Well, I might say that they're bad. But I won't say that they're indemic to Combat as War. They certainly are one version of CaW, sure. But I'd personally label that a CaW fail state. And acting on OOC knowledge is much more common in - and the body backbone of - Combat as Sport. "The GM wouldn't throw anything at us that we couldn't handle". Need I say more?
I'm sorry that your modules and GMs were bad. While neither will ever be perfect, both can be much better than you have described.
IMO, modules are best if run straight as a starting state of the world, by a good GM who knows how to handle things going off-script in a way that custom tailors the level between "impartial rules arbiter" and "for fun" at the correct level for the group. And, for me, that's pretty much "impartial rules arbiter".