What makes you believe this was written by an LLM?

Because it has many of the typical 4o stylistic tics like 'it's not X, it's Y' or enumeration or the em dashes, or the twist ending.

It's not 100% unedited ChatGPT and far from the most blatant instance that has caught my eye (they've started showing up in the New York Times and New Yorker as well, have you noticed that?), but certainly sounds like that was used: "Writing compels us to think — not in the chaotic, non-linear way our minds typically wander, but in a structured, intentional manner." "This is not merely a philosophical observation; it is backed by scientific evidence." "Importantly, if writing is thinking, are we not then reading the ‘thoughts’ of the LLM rather than those of the researchers behind the paper?" "overcoming writer’s block, provide alternative explanations for findings or identify connections between seemingly unrelated subjects."

(Note that this is particularly ironic because as the op-ed notes, if they did use it, they are required by Nature to disclose this... https://www.nature.com/articles/d41586-023-00191-1 But of course, how would anyone ever prove they did so? You know how difficult it is to get Nature to retract even blatant fraud.)