In my opinion it should remain a shell thing. Adding tilde expansion just complicates the implementation of the tool. Now you need to know the current users home directory. And some tools might implement it incomplete so that '~' works but '~name' does not work.

In POSIX shells '~name' expands to the home directory of user 'name'

  $ echo ~bin
  /bin

Now your tool need a way to query home directory for any user including system users. Depending on NSS configuration this is more complicated than just reading /etc/passwd.

All for the rare case that someone passes a file path starting with tilde and wants it to be expanded. IMO, when you provide a file interactively you do so through a shell and tilde expansion is handled by the shell and otherwise just provide the actual file path and do not rely on the tool doing additional expansions.

PS: I mixed up TUI and CLI program a bit in my head. For an interactively used TUI program it might be beneficial to implement tilde expansion (but then it should be as complete as in Shells). A CLI program should not do magic stuff like tilde expansion.