I think folks forget some of these devices have very low memory/disks, which makes adding stuff tricky. And there is no busybox under-the-covers to even expose. busybox assumes the underlying files/system is exposed, which hasn’t been Mikrotik’s philosophy to allow. Kinda think if managing the underlying OS is what you want to do, flashing OpenWRT seems like a better approach…than trying to make RouterOS more like OpenWRT.
NOW if you asking if Mikrotik should map more of the POSIX/“busybox” into RouterOS equivalents, different question. And think some progress on the multiyear request list for more built-ins function into the scripting language would go a long way to making the scripting better, than replacing it.