I was looking at a production service we run that was using a few GBs of memory. When I add up all the actual data needed in a naive compact representation I end up with a few MBs. So much waste. That's before thinking of clever ways to compress, or de-duplicate or rearrange that data.

Back in the day getting the 16KB expansion pack for my 1KB RAM ZX81 was a big deal. And I also wrote code for PIC microcontrollers that have 768 bytes of program memory [and 25 bytes of RAM]. It's just so easy to not think about efficiency today, you write one line of code in a high level language and you blow away more bytes than these platforms had without doing anything useful.