There's nothing perpetual about it. You can unsubscribe at any time and your Vision Pro will keep working just fine.It's honestly less about the money than it is getting stuck in this perpetual dependent relationship. People like to buy products and use them without a marriage contract.
Yes, without iCloud you're going to lose the ability to sync your pictures across multiple devices, but a P2P sync option would be a big usability compromise compared to iCloud anyway.
In essence, by not supporting P2P sync, Apple is taking away from the user the least convenient and more cumbersome option to sync pictures across multiple devices.