This fallacy is important for planning your project and its budget. Building and maintaining a network for a distributed system costs both time and money, regardless of whether you deploy on-premises or in the cloud – it's just a matter of when you pay the cost. Try to estimate the costs of the equipment, the data to be transferred (cloud providers charge for this), and the required manpower.
If you're relying on compression, be wary that while this reduces networking costs, it can increase the price for your compute. In general, using binary APIs such as gRPC-based will be cheaper (and faster) than JSON-based ones, and those are still cheaper than XML. If you send images, audio, or video, it's a must to estimate how much this will cost you.
