"They" have considered it and tried it, but had to revert the change. Dash is in Debian primarily for scripts, not for interactive usage. If you want to use dash with libedit, you have to compile it yourself, unfortunately.

"The dash shell is actually reasonably pleasant for interactive use when compiled with libedit."

For me it's the preferred interactive shell. When compiling dash with libedit, I edit dash source to enable tabcomplete. Then it feels more like NetBSD.

I've been running an experiment using busybox bash instead of dash as both interactive and scripting shell; have discovered numerous busybox idiosyncracies as a result. One thing I like about busybox bash is it's command history search: Ctrl-r. A bit faster than libedit.

NB. "set -o vi" can be abbreviated to "set -V"

busybox "ash" is littered with "bash-like" features. Searching command history using Ctrl-R is just one of many. IMO, it has enough changes from NetBSD sh and Debian sh that it is neither ash nor bash. Regardless, I should have referred to it as "busybox ash". Apologies for the inadvertence.

busybox includes a config option to include a "bash" applet name that points to "ash"; typing "busybox" one will then see "bash" listed as an applet, but is the same shell

Sometimes when compiling software, authors insist on using bash scripts at compile-time rather than sh scripts. Trying to use busybox ash to run these scripts will fail because there is no applet called "bash". There might be another workaround but I find it useful to compile busybox to include a "bash" applet name.

Another nice thing about busybox ash is that it's easy to recall and edit previous commands by editing the .ash_history file.

Normally I would do this in NetBSD sh using the builtin "fc"; dash excludes the fc builtin.

I understand that busybox bash is specific to the windows port.