The other problem with this idea is that natural languages contain quite a bit of redundancy, which is why speech and writing can be decoded even over very nois

The other problem with this idea is that natural languages contain quite a bit of redundancy, which is why speech and writing can be decoded even over very noisy channels. It’s hard to make language more compact without removing some redundancy. That being said, this has been attempted before: see https://en.wikipedia.org/wiki/Speedtalk https://en.wikipedia.org/wiki/Speedtalk and https://www.zompist.com/kitlong.html#howmany https://www.zompist.com/kitlong.html#howmany, and especially https://web.archive.org/web/20000503004430/http://fatmac.ee.cornell.edu/%7Eben/speedtalk.html https://web.archive.org/web/20000503004430/http://fatmac.ee.... for a detailed attempt.