It might be helpful to actually measure the font size you are seeing and the Mac says it is displaying. A true 12 point font is 12/72" high, or 4.23mm high, and this height is measured from the top of the letters to the bottom of the descenders. For example, the top to bottom of the characters in "TgTgTgTgTgTgTgƒƒƒƒƒƒƒHelp".
To see what Mac scales its font sizes as, create a file with a name like that, measure it as displayed on-screen in Finder, convert it to physical points and compare it to what Finder thinks the font size is in View / Show View Options / Text Size.
On my 15" MacBookPro8,2 Early 2011 with 1680x1020 resolution (130dpi), what Finder calls 12 point text is more like 2.5mm or 7 point text. Finder's 16 point font is like 3.5mm, or 3.5/25.4*72=10pt font.
If I use the System Preferences/Display/Display/Scaled/1280 x 800 setting (100dpi), then Finder's 16 point font is physically 4.5mm high, or 12.75pt.
If I scale to 1152x720, (~90dpi) then Finder's 16 point font is physically 5mm or 14.7pt high.
Scaled to 1024 x 640 (~80dpi), Finder's 16 point font is physically 6mm or 17pt.
Comparing the Finder font sizes with the sizes of the top menu bar, it appears that the Menus match Finder's size 15 text. (Try a file named 'Help'.)
My 50+ year-old eyes are better off with the physically 3mm or 8.5pt fonts resulting from 1280x800 scaling and Finder's font size 12. With that, I get reasonable real-estate on my laptop screen and proportionality with the rest of the menus and everything else. My 1920x1200 desktop monitor doesn't need the scaling and has more real estate.