I think the article misunderstood the debate... the debate is (or at least was) about gitflow, and specifically about having git branches per environment. So there are git branches for dev, staging, etc, all the way to prod. And git changes become deployed on the respective branch.

Trunk based development is about having a single master (sorry, "main"), and generating deployable artifacts from there, and then the remaining environments have only deployments of versioned artifacts.

Unless I'm missing some new debate about the value of PullRequests, but that sounds extreme.