The default HTML styles are fine as they are. You can create a document with no custom styles and it'll be perfectly legible. More to the point, old sites with

The default HTML styles are fine as they are. You can create a document with no custom styles and it'll be perfectly legible. More to the point, old sites with unstyled HTML documents will remain perfectly legible and structured. One could argue otherwise that the needs of the web have outgrown HTML as it was originally intended.