It’s not tinfoil at all, it’s just normal decision making.
You have 10k customers (out of a possible 20k) - do you upgrade your lines where it would make you fastest by far, or do you upgrade your lines where you’d just be as fast?
The second probably has fewer customers, the first will get you new customers.
I suspect there isn't just because they don't really need to "coordinate" which would cause anti-trust issues, they can just "watch" and adjust based on what they see.
You have 10k customers (out of a possible 20k) - do you upgrade your lines where it would make you fastest by far, or do you upgrade your lines where you’d just be as fast?
The second probably has fewer customers, the first will get you new customers.