Not all subscription based services are malicious. Case in point: Bitwarden is incredibly cheap (10€ per year) and is the best password manager I have ever used. Also services that need constant upkeep costs, such as your carrier, ISP, perhaps even a VPS (I use Hetzner for that), have simply no way to be one-time payments.
Eh, everything points to a mistake. Bitwarden not only rectified it ASAP but also made the switch to GPLv3. The latter is not just something you do to please people, you need to understand the legal ramifications it can have on your business, so it very likely was a change that's been discussed before all of this.