fiber – Largest current bandwidth between US datacenters?

Want to improve this question? Add details and clarify the problem by editing this post.

This post was edited and submitted for review 4 days ago and failed to reopen the post:

Original close reason(s) were not resolved

I am trying to estimate the high end of bandwidth between US data centres, especially in the context of high-load applications such as AI training.
My current approach is as follows:

With these assumptions, I would arrive at a upper estimate of bandwidth of 400 Gbps x 80 channels x 8 fiber pairs = 260 Tbps.
Is my BOTEC very off? If so, why?