Give one reason as to why Williams v Roffey Brothers’s practical benefit principle is significant in the English contract law?

Try to make it as interesting as you can. (Put in personal opinion) Focus in terms of contract variation and possibly payment for less cases (like Pinnel’s case, Foakes). Look at broader issues of how it is significant in terms of the doctrine of consideration or even common law in UK. Also, provide opinion for improvement if the significance is negative. No need for introduction or conclusion. The essay should only focus on 1) the reason why it is significant and 2) if any, personal opinion of possible improvement/way forward.