It used to be just best practice to shrink down anything over the wire as much as possible. When I started building websites around 1996, every byte counted and

It used to be just best practice to shrink down anything over the wire as much as possible. When I started building websites around 1996, every byte counted and you would "optimize" every GIF image carefully to the smallest size you could, taking it down to 256 or 16 or even custom colors - like 6 colors in the VGA spectrum that looked good enough with dithering. It kinda didn't matter from 2010 on. But one area I've written my own specific "compression" methods in, for the last few years, has been in shipping data in and out of webworkers (in-browser or in Node). This is where there's still enough of a performance penalty on a lot of devices for sending 1MB that in use cases where you're spawning lots of workers to run long tasks, it makes sense to trade time to compression for a smaller transfer size.