[latex] Breaking a list into multiple columns in Latex

Another option to avoid nesting two different environments (like multicols and enumerate).

The environment called tasks from the package with the same name seems to me very easy to customize thanks to a variety of options (pdf guide here).

This code:

\documentclass{article}
\usepackage{tasks}

%\settasks{style=itemize}

\begin{document}
Text text text text text text text text text text text text 
text text text text text text text text text text text text 
text text text text text text text text text text text text.

\begin{tasks}(2)
\task[*] a
\task[*] b
\task[*] c
\task[*] d
\task[*] e
\task[*] f
\end{tasks}    

Text text text text text text text text text text text text 
text text text text text text text text text text text text 
text text text text text text text text text text text text.
\end{document}

produces this output

tasks

The package tasks was updated in August 2020 and it was originally created specifically for horizontally columned lists (see the screenshot just above here), the motivations behind this are resumed in the guide. If such arrangement of the items/tasks is acceptable, then this may be a good choice since it keeps - IMHO - the code tidy and flexible.