If you are doing just one or two things at a massive scale (Dropbox storing files), it makes sense. But, we are talking about Snap Inc, the infrastructure, and services it needs. A single high-speed intercontinental fiber cable costs 400 Million $ (https://techcrunch.com/2016/10/12/google-and-facebook-are-bu...). To build a service like CLoudML (Hosted TensorFlow), you need to write software (TensorFlow), build the ASIC Chips by manufacturing / by partnering with a chip manufacturing company like Intel / Samsung / Qualcomm, you need custom networking software and hardware to scale massively for data workloads (Andromeda), years of research to build these tools, you need to create your own programming language (Go and Dart) to be able to scale your development to these levels, you need to build data centers in multiple regions, you need to build DeeLearning models for cooling your data centers (https://deepmind.com/blog/deepmind-ai-reduces-google-data-ce...), ...