Sure, what I actually had in mind was if there was only a 4 way rewireable Wylex there in the first place the space for a replacement can be limited (if of course the replacement occupies the same spot)
In a small house where the kitchen is the utility room, you might have a dishwasher, washing machine and tumble drier all on together for over an hour. Ironing the previous load while the next one is washing and drying. A cuppa, kippers on toast. It's not a given that a 20A circuit won't get a little warm!
I don't disagree that other designs work, and multiple radials is certainly possible, but it is a convenient and resilient circuit for variable loads.
Aside from their ability to 'just get on with' periods of heavy use, they are probably the circuit that it is easiest to prove is in an excellent condition and discover modifications via the extensive tests that are possible.
To clarify, I don't think anyone is saying that we can't possibly do without them. It's about whether there are benefits to choosing to use them.