Alas, Lucian is missed so often
That is my feeling, that if you had just had an electric cooker fitted then you would want an electric kettle but might not have many (if any?) spare 13/15A sockets already.
The 13A plug with internal fuse of course means it is not important if the supply is 16A or 45A, etc. Having a 15A unfused outlet off 30A/45A seems a risk though? Did the oldest has their own rewirable fuse just for the outlet?
For a new kitchen with lots of sockets there is no need for the cooker+outlet fixture, but for many existing kitchens that extra socket is handy!