Although I've given both zsh and fish a try these past few years, the thing is that I keep falling back on good old bash. I'm not sure why, to be honest. I suppose my main reasons are that: first, I tend to like simple things; second, bash is always the default shell on remote systems; and third, when writing shell scripts I always do it in bash. So, why not continue using bash as my main shell anyways? It does what I need anyways. In any case, even after so many years running bash, I just discovered that there is such a thing as bash-completion which can be easily enabled. I followed the directions from the Debian Wiki, and it worked flawlessly. I only had to make sure the package was installed, and then add the following to my .bashrc:

# Enable bash completion in interactive shells 
if ! shopt -oq posix; then 
	if [ -f /usr/share/bash-completion/bash_completion ]; then 
		. /usr/share/bash-completion/bash_completion 
	elif [ -f /etc/bash_completion ]; then 
		. /etc/bash_completion 
	fi 
fi