Re: Purely commercial, not technical decision
Not defending them, but I would imagine there are many more updates required to running Sage. Tax rules change relatively frequently, especially if dealing with cross border jurisdictions. On the other hand, none of the private, commercial or sensitive data from an on-prem perpetual licenced install should be leaving the LAN and heading off to Sage central. At most, a licence authentication before receiving the same data updates everyone else is getting.
On the gripping hand, if a licence is "perpetual", why does it need regular and/or frequent authentication in the first place?