I think there’s a distinction to be made between solutions which are client-side, versus those that are server-side, or at least have a server-side component that is functionally necessary.

For the first category, the termination of a subscription shouldn’t lead to denial of access to the current build of the software: it should remain functional in the absence of lower-level updates. Ideally this software is sold as a one-time purchase, having life-time free updates bundled, or sell upgrades on a versioned basis; but a subscription fee for future updates seems perfectly reasonable too, if the previously stated conditions are met.

For the secondary category I believe it’s in the service’s right, to provide it’s products on the basis of its own terms and conditions; that is, if it doesn’t employ morally questionable practices, like: outpricing other services using venture capital, for the purposes of attracting a user-base for future exploitation (by raising fees, or by turning the user into the product; despite an ever decreasing value proposition: i.e. venture capital enshittification).