Microsoft 365 or Office 2021? Also considering WPS Office with its AI capabilities

I’ve decided it’s finally time to get Word on my Mac, Google Docs just isn’t cutting it anymore. I still have an ancient Windows PC running Office 2010 (I know, ancient lol), and it’s served me well. Now, I’m torn between getting Microsoft 365, which I’m not fond of because of the subscription model, or Office 2021 with a perpetual license.

From what I’ve seen, 365 constantly updates and changes its interface, which honestly drives me nuts. Am I being old fashioned here, or is it valid to want a stable version like Office 2021? Also, is the “Student” version of Office 2021 the same functionality wise for Word, Excel, and PowerPoint as the “Business” version, apart from Outlook?

I mainly use Word to write books; it’s just easier to share manuscripts with my editor and beta readers since everyone has Word. But I’ve also been hearing about WPS Office, which is said to be quite similar, and apparently there’s WPS AI for editing help. Should I consider that before purchasing any Microsoft suite? I’d love to get some advice or personal experiences.