Have a look at https://mywiki.wooledge.org/BashPitfalls#echo_.24foo

Most of the time, "echo" works as you'd expect, but as it doesn't accept "--" to signify the end of options (which is worth using wherever you can in scripts), it'll have problems with variables that start with a dash as it'll interpret it as an option to "echo" instead.

It's a niche problem, but replacing it with "printf" is so much more flexible, useful and robust. (My favourite trick is using "printf" to also replace the "date" command).

Also, here's some more info on subtle differences between "echo" on different platforms: https://unix.stackexchange.com/questions/65803/why-is-printf...