Why is arch linux bash better than Ubuntu bash?

Both of them use bash, but the one used on arch linux has way better auto-completion. But why is that? Both of them claim to use normal Bash, so how can that be true? ---- I forgot to clarify that what I meant by Arch linux was it's installation ISO. I have never tried out the actual Arch linux. Also, I have tried ZSH and the auto-completion on ZSH seems similar to the arch bash's. Is it because of an additional package? --- The differences between Arch's Bash and Ubuntu's Bash is noticeable enough to understand what I'm talking about. Here is a little example: cat ./ (The command is not entered) - **Arch's Bash**: When I press TAB, all possible options are shown in a nice and very organized way, and when I press the down and up arrow keys, it allows me to select from those options. - **Ubuntu's Bash**: When I press TAB, all possible options are shown, sometimes in a nice and fairly organized way, but arrow keys just scroll between history of commands, not options. Not convenient. This is one way Arch's Bash is better than Ubuntu's Bash. This is assuming there are not too many options and around 16 options to choose from. Arch's ISO is the version released on July 2025.