SaaS is a menace. There are lots of valid use cases - streaming service, cloud storage, online games come to mind - but otherwise it means users basically lose yet another part of their ownership. I view software as a tool, like a hammer. You don't want your tools to break unexpectedly, phone home, or change their functionality without your explicit approval.
For a price I expect the developer to release bugfixes and security patches, nothing more. Feature updates and compatibility fixes can be billed. They should be worth the update price. Honestly, most software can be "finished": when it does its main function well, and has compatibility, why bother? Who even looks at changelogs of Jira, Photoshop or Office nowadays? Users are more afraid of what will be removed rather than what they gain.
It's each maker's choice to set up a scheme, but I see the industry sliding to exploitation by default.