I'm surprised no-one has mentioned 3Blue1Brown yet, who is perhaps the single most influential figure in popular mathematics today. https://www.youtube.com/@3blue1brown
+1 for Rick Beato. His "what makes this song great" series is lovely. I discovered his video on [Bohemian Rhapsody][1] from the same series and then gradually all of his other content.
I'm surprised no-one has mentioned 3Blue1Brown yet, who is perhaps the single most influential figure in popular mathematics today. https://www.youtube.com/@3blue1brown