Even at pro and high level, the difficulty of a strategy factors into how broken it is.
What is this in response to? Using utility effectively is fundamental to tactical shooter gameplay, it isn't some frame-perfect five-man I-trained-my-whole-life-for-this-one-moment operation like you're making it out to be.
A lot of Characters can't deal with an OP in the slightest. While your reaction to that might be the iron level "jUSt piCK The gOOD AGaINST oP chArAcTErs", that's a fundamental design issue. ... If there are only two people on a roster that can deal with a OP, and they die, then the round is over.
If you don't have a way to deal with an operator posted on a corner, you probably don't have a way to deal with a rifler posted on the corner either, which means you're going to rely on a dry peek which theoretically should result in you being punished - something that I think is part of m1xwell's main point. An operator simply tips the odds further in their favour, but whether it is an operator or a rifler that is holding the angle, not having the correct utility means it should not be a scenario you should expect to win in the first place.
On top of that, you've framed it as though this is an issue with the operator, but it's a design decision that persists through all of VALORANT. A Brimstone can't deal with well-placed Cypher wires, a Sage has no way to force someone out of a cubby, a Raze has no way to block a sight line. Unless they add universal utility, this 'problem' is always going to exist in VALORANT.
So the attacking team blows 3 people's worth of utility on countering the OP.
This is another part of m1xwell's point that people seem to be ignoring: you are not blowing utility to specifically counter the operator. You are using utility to make the area safer for you to push - this INCLUDES negating operators. You should be using your utility to get onto site regardless.
And I don't really understand why you're making it sound like using 3 agent's primary utilities to enter a site is an absurd cost - it should be expected for a typical site execute. Since you've brought up CS:GO utility previously, there are several site executes that will use the majority of the T-side smokes and molotovs, even if they're just expecting to deal with 2 riflers on a standard set-up. It's pretty normal.
Attacking utility in this game is just the worst, with limited ranges and weird requirements.
Admittedly it's unfortunate that a number of utility in this game that would otherwise be really helpful for clearing out defenders, when used as an attacker, requires you to expose yourself to danger in the first place.
The game is already defender sided, allowing the OP basically no danger.
Not really a point. CS:GO is also inherently defender-sided. In CS:GO, you are also expected to use utility effectively to deal with an AWP.