This definitely interests me as well. Another 'wasteful' mechanism is the nearly-ubiquitous use of JSON over a more optimized format like protocol buffers, etc... It reminds me of another HN discussion here: https://news.ycombinator.com/item?id=9761667

I understand that economically the savings in development time usually outweighs the bandwidth costs, but I would be interested in any analysis on how wasteful this is overall.