Do you choose your block size when you use dd? For me, on multiple OSes and oldish hardware, $ dd if=/path/to/iso of=/path/to/disk bs=1M seems noticably faster than etcher. I suspect thats not even the optimal choice

Edit:noticed this is sort of a repeat answer, leaving it so the people saying its slow can copy/paste and try it out.

I highly doubt that it's faster than a dd with proper blocksize. With inefficient I mean that it's an Electron application.