Matthaus, thanks for chiming in, especially from your developer perspective.
It is such a challenging problem. I think having a server-side element does make it easier to sell as the customer can see they are “paying for something tangible”, rather than just promises of “future development”.
The continuous improvement cycle is also a reason given for much development. But then I subscribe to YNAB, who promised lots of ongoing improvements. I love that service and it gives me value, but in one year they have mainly delivered bug fixes (their errors, not user errors!) and after a year have just released full version mobile apps. So we had to wait a year of subscription time, and got a ‘big splash’ release after that time!