Yeah, I agree. If all transactions are reported and treated like a sale.

I just have personal experience where the person offering from one side often wants to avoid the tax. In Australia we have 10% GST/VAT. Pay someone and there is 30% payrol tax (even as a sole trader). Then 12% mandatory pension contribution.

So the $5000 website/landscaping turns into 3k cash in hand.

Enticing to avoid this if you can, but I am risk adverse - clients pay me off the back of this. It balances the risk appetite of a business owner who could cut corners, with me sayng not to. If they do, at least I made the risk clear.

But your point is valid and correct. There is nothing wrong with contra deals where it's booked properly.