Short answer
No — iCloud Private Relay and a VPN cover different scopes. Private Relay protects IP-address and browsing privacy inside Safari. A VPN encrypts your device's traffic more broadly, not just inside one browser. Which one you need depends on what you're protecting: browsing inside Safari, or everything your phone sends and receives.
What a VPN is actually for
A VPN creates an encrypted tunnel between your device and a server you trust, so that whoever is running the network you're connected to — a coffee shop router, a hotel Wi-Fi hotspot, an airport access point — can't see or tamper with your traffic. That's the core job of any VPN, including Casper's Cloak, which uses the WireGuard protocol to build that tunnel on iPhone, Mac, and Android.
Where a VPN alone stops
A VPN encrypts the pipe between your device and its exit point. On its own, that doesn't include deciding which destinations are safe to reach through that pipe — filtering out known malicious or tracking domains, or catching things like phishing hosts, is a separate layer of protection.
What Casper's Cloak adds on top
Casper's Cloak combines a WireGuard VPN tunnel with DNS-level filtering that blocks known ad and tracker domains, plus a machine-learning layer that scores domains in real time to flag phishing and malicious hosts. This coverage applies across the apps and domains you haven't explicitly excluded — Casper lets you choose services, domains, or IP ranges to route outside the tunnel if you need to, so coverage follows what you've chosen to route through it. It's one subscription across iPhone, Mac, and Android, built for people who want more than just an encrypted tunnel.
The practical takeaway
If your main concern is browsing privacy inside Safari specifically, a browser-level privacy feature addresses that use case. If you want your phone's traffic encrypted on untrusted networks and a filtering layer on top of it, that's a broader job — the one a VPN-plus-filtering product like Casper's Cloak is built for. See current plans at casperscloak.com/subscriptions.