It's not just an anti-ship cruise missile per se - it's the replacement for Storm Shadow for the RAF and SCALP for the French AF.
It will also be a replacement for Harpoon for the RN and carried by ships as small as the Type 26 in VLS.
If it ends up being based on the MBDA concept, it will be capable of Mach 5 and a range of 300km compared to 1,000km for TLAM, 560km for Storm Shadow and 148km for Harpoon.
More details here:
https://www.navylookout.com/royal-na...siles-by-2028/