The font atlas is definitely still worth it. For example: your comment, which fits in a single browser tile, is made up of 735 drawn glyphs. There are 50 distinct glyphs used (not counting italics because I'm lazy).
Assuming it takes twice as long to draw a glyph into an atlas but half as long to draw it once it's in the atlas, an atlas that starts completely empty will speed up text drawing for your comment by 66% (735 divided by 50 * 2 + (735 - 50) * 0.5, which is 442.5). And this underestimates the savings by a lot (drawing glyphs from an atlas is much more than two times as fast, and some glyphs are probably in the atlas already).
Assuming it takes twice as long to draw a glyph into an atlas but half as long to draw it once it's in the atlas, an atlas that starts completely empty will speed up text drawing for your comment by 66% (735 divided by 50 * 2 + (735 - 50) * 0.5, which is 442.5). And this underestimates the savings by a lot (drawing glyphs from an atlas is much more than two times as fast, and some glyphs are probably in the atlas already).