Why Merlin can cover roles an Osprey fleet would complicate

Would Osprey be better than Merlin for British naval roles?

No; Merlin already covers several essential roles, while adding Osprey would create a second support and logistics burden.

Replacing Merlin with the V-22 would still leave the force needing Merlin for anti-submarine warfare. Ospreys would therefore add another aircraft type, logistics chain, and deck-management burden. A carrier air group centred on F-35B and Merlin lets two aircraft families cover strike, air defence, AEW, ASW, and commando transport. In 2020, Britain expected to keep Merlin working in the near term and look to the U.S. Future Vertical Lift programme for its successor.