Links are a key factor in this navigation process. When visited links don’t change color, users can unintentionally revisit the same pages repeatedly.
Do’s and Don’ts of Web Design
Nick Babich

I love things like this. Like all of responsive design. The web is inherently well-designed, and then we come in with CSS and ruin everything. The web was doing this before we even had CSS, and now it’s a “good UX” recommendation. 🙈