No, UUIDv8 offers 122 bits for vendor specific or experimental use cases. If you fill those bits randomly, you get the same amount of randomness as a v4. The spec is explicit that it does not replace v4 for random data use case.

> To be clear, UUIDv8 is not a replacement for UUIDv4 (Section 5.4) where all 122 extra bits are filled with random data.

https://www.rfc-editor.org/rfc/rfc9562.html#section-5.8-2