CR may not be perfect, but IMO it's worlds better than before it existed. I started with the Basic set and 2e, and in those days if you wanted to create a balanced encounter, you just kind of eyeballed it and hoped your guess was somewhere in the right ballpark.
Nowadays, I still sometimes eyeball it, but at least I have guidelines to fall back on if I want a sanity check.
I actually think this falls more under the Combat as War/Sport distinction. If you have a DM who runs a CaW game and players expecting a CaS game then you're going to have a problem. However, that is more an issue of communicating and managing expectations. If you tell the players that they shouldn't expect encounters to be fair, then there's no reason for them to expect fair encounters. Of course, whether or not a given player actually wants to play in that style of campaign will be up to the individual, but there are certainly players who will.
And that’s my point in a nut shell. In following a scheme of fair and balanced encounters, it’s the “illusion of challenge” I referred to in my original post.
They want to
feel challenged, but don’t want the risks of an uncontained confrontation. Which is fine, I’m not saying one play style is inheritantly better than the other.
You can test this, offer to run your group a DCC funnel with the randomly generated 0 level characters. Explain to them the concept.
Your group might be game for it. They might reject it.
If they reject it, I can predict the reasons are :
A) “we don’t want to play with that level of lethality”
B)”we don’t want to play with randomly rolled, potentially low stat characters”.
That there is the inherent challenge of the game. Make do with what you’ve got and become a hero through surviving. To control for system variance, you could also convert a funnel adventure for a 1st level 5e group. It would massively break the basic “agreed illusion of challenge” expectation. See how they react.
Instead, many players prefer the power fantasy. They want to make their character, have control over every aspect of their hero, bravely overcome the (balanced) odds and win the epic quest.
It’s fine, some want to play Diablo, swatting demons aside through their builds than play dark souls. And that’s cool, but that challenge isn’t on the same level.