My main concern with any online based software

1. - If there is an internet issue, either from your side or the server side, you can not process
2. - You never own the software, but are always paying, irrespective of the so called free upgrades - this is called "Rental Seeking Investment" by the service provider.
3. - Being online means that you are at the mercy of the service provider.
4. - You have no control of any future price increases on the subscription, again placing you at the mercy of service providers.
5. - The day that you have an issue or are unhappy with the service provider, and decide to withhold payment or do not pay the monthly subscription, means that you are left out in the cold, as you will have no access to your original data, due to being locked out.
6. - Also difficult to move to another service provider once you are committed.

Buying software outright means that it is yours for ever, paying monthly means that you never own the software and are only paying to use the software.
In certain instances this is acceptable, but in the cases which you are going to have data access for years past and future, then this may be an issue due to lack of no access.

If a service provider can not guarantee their software, as is usually part of their marketing sales pitch to go the subscription route, then it means that it is not good software in the first place.