From a Google Pagespeed Insights test it seems my MediaWiki website lacks text-compression;
reading about this, it seems I lack this because I don't have Gzip compression on.
I Ran this gzip test and it seems indeed my website lacks Gzip compression.
Interpreting this article, I tried to add Gzip by adding to following input to the end of
$wgUseGzip = true;
Yet Gzip wasn't added.
I find no other manual literature about this
How to allow Gzip for a MediaWiki website?