While I agree, there is no reason NOT to use a perpetual license (e.g. for Excel 2016), unless you really, really need the subscription-based version.

You may notice the last edition of softwares that had perpetual licenses but moved on to subscription model tend to be very expensive today as they are no longer sold and people know how to count. So, let's use the opportunity while it lasts as I don't believe the end of perpetual licensing for Office (or Windows for that matter) is far away.