This blog touches on why Elixir is doing so well-- it's easy to extend and add to the language, pull requests are welcome and (most of the time, anyway) the Jose appreciates and integrates additions to the language. (He once rejected something that I disagree with, but on the balance he's doing a righteous job.)
In fact, it's the only language I've contributed to. In large part because the bar is so low and the process is so reasonable.
Sometimes you are dealing with fields that are packed into a 32-bit (or 8- or 16- or 64-bit) word where one field is bits 0 through 5 and another field is bits 6 through 9 and a status bit in bit 10 and another field is bits 11 through 31. Thinking about those in hex is much harder than if they were all nice multiples of 4 bits in size. Yes, C programmers have been dealing with this for decades (no binary literals in C), but wouldn't it be nice to write each of those fields in binary (with underscores separating them) and let the machine do the rest?
In fact, it's the only language I've contributed to. In large part because the bar is so low and the process is so reasonable.