I really hate most subscriptions, because the prises are often too high, they rely on locking stuff behind paywalls, instead of providing a good service.

Here is the difference, I am ok paying monthly for storage space, servers, and hosted/managed open source web services, because there is competition and standard interfaces there. They do not hold you hostage to their service, what they provide is good on its own.

I GOG invests money into writing open source libraries, apps and APIs to efficiently and easily share save games between devices. Let people self host the open source backend, but offer up a subscription for a managed instance, with maybe some voting rights for new features to be integrated into the open source backend, then I would be willing to support this.

And other stuff like this.

Use subscriptions to offer good services, which also allow you to improve the whole ecosystem, while also not putting yourself as the gatekeeper, and locking people into their service.