This seems like very basic contract law 101 stuff.
The promise of payment is the consideration. A contract is literally an exchange of promises. When you go into a car dealership and buy a car, they are exchanging a promise (you get a car!) for your promise to pay them.
The refusal to pay is a failure to live up to the promise - that is what makes it a breach of contract. If not paying meant consideration didn’t exist, then nobody would be able to sue for breach of contract for non-payment. If breach meant the contract was invalid, you wouldn’t be able to enforce the contract.
The promise of payment is the consideration. A contract is literally an exchange of promises. When you go into a car dealership and buy a car, they are exchanging a promise (you get a car!) for your promise to pay them.
The refusal to pay is a failure to live up to the promise - that is what makes it a breach of contract. If not paying meant consideration didn’t exist, then nobody would be able to sue for breach of contract for non-payment. If breach meant the contract was invalid, you wouldn’t be able to enforce the contract.