#1: Was this article written by an LLM? The phrasing implies there's a high chance #2: Is your company sending spam emails? I don't know how Gmail's system works, but I will mark any unsolicited email from businesses as spam. Perhaps Google uses that as a heuristic?
It also goes the other way, if enough people click "not spam" and interact with your mails, your reputation gets better. I'm currently trying to do that with my personal email/domain - will probably take some time though. For now, my friends say my mails land in spam even though I get a 10/10 score on mail-tester.com and similar sites.