Grass is green and hyperlinks are blue.

[Xairbusdriver]

But why?! Here's an interesting walk through (computer) history with a few facts and lots of opinions.

dist://ed, Elise Blanchard, August 26, 2021

In my own weather web site, the dominant background color is 'sky blue' so I decided to use a different color for links, including a high contrast background color. "Concrete" is a valuable building material, but it is not always required or even desired.

[kimmer]

I read this via a TidBITS article a few days ago and found it interesting.

[Xairbusdriver]

That is one reason for keeping the underline and adding other contrast options (usually defined in CSS). Screen readers will also recognize the html "anchor" and "href" tags.
    <a class="normal rounded"
        href="my_journal_view_main_dn.php"
        title="Journal Entries"
        target="_blank">
        &nbsp;Journal&nbsp;display&nbsp;
    </a>