Archinstall 4.0 is out today and just in time for the April 1 monthly refresh to the Arch Linux installer. With Archinstall 4.0, this Arch Linux OS installer is now using the Textual TUI library rather than the Curses library.

Archinstall 4.0 is now using Textual rather than Curses to provide a more modern text-based user interface. THe developers feel this provides a better looking terminal-based installer for Arch Linux rather than the mature curses library.

I would say it does indeed look more modern and nicer than their former UI:

Archinstall 4.0 also brings updated translations, instructions for booting Arch ISO in a VM, enabling GRUB UKI menu entries, and a lot of other code refactoring and improvements.

More details on the shiny new Archinstall 4.0 release via GitHub