It's not though. You can still buy standalone non-subscription copies. It's literally your choice. That and the subscription works out to be a whole lot cheaper overall anyhow.In my country, a copy of office 2016 home business (with outlook) costs $400 for a single copy. A yearly subscription of office home premium, that comes with the same software costs $80, but can be used on 5 PC's and 10 mobile devices and includes 1tb one drive storage. Now, doing the math, if you had to buy 5 copies of the standalone version (for comparative reasons) it'd cost you $2000.
You'd have to be paying the subscription for roughly 25 years for it to cost as much as just 5 copies of the standalone version, plus you get more features overall and as long as you pay, you're always on the latest edition of office, so you'd get 2019 at no additional cost.I don't currently pay either, i have my pirated 2016, but once I'm able to afford it again, I'll definitely do 365.