Not sure about English law but in Roman law (and derived systems as in South Africa) the emphasis is on specific performance as a first resort — the court will seek to implement the intention of the parties embodied in the contract as far as possible.
This is actually American law, neither English nor Roman. While it is derived from English common law, it has an even stronger bias against specific performance (and in fact bright-line prohibits some which would be allowed in the earlier law from which it evolved, because of the Constitutional prohibition on involuntary servitude.)
Cancellation is a last resort.