Very much so if you are using Windows, Android, OpenJDK Java development kit, PlayStation 3 & 4, PS Vita, and any other Operating System that uses FreeType that implements the hinting feature.
Also On Windows, projects like gdipp and MacType aim to override the
system renderer with FreeType.
It is part of TrueType
TrueType is an outline font standard developed by Apple and Microsoft
in the late 1980s as a competitor to Adobe's Type 1 fonts used in
PostScript. It has become the most common format for fonts on the
classic Mac OS, Mac OS, and Microsoft Windows operating systems.
Question: So is hinting still relevant in 2017 and onward? When would be the point where it becomes obsolete? (appended edit)
Answer: Not likely considering all the platforms that use it, but it is hard to predict the future
Question: Edit: Is inherit used on this site set to 9 hinted?
Answer: Only if you are not using Mac. Mac ignores hinting.
This link here explains a bit more.
It gets into the differences between how Mac and Windows rendering fonts.
Mac OS vs. Windows A lot has been written about how Mac OS renders
text compared to Windows. I will not go into details here, but the
primary difference is that Microsoft’s rasteriser tries to align
characters to whole pixel grid, with the result that ‘Regular’ weights
look lighter, ‘Bold’ weights look heavier, and subtle details of
design can be lost at small point sizes. Apple’s rasteriser tries to
preserve the design of the typeface as much as possible, sometimes at
the cost of image clarity. Windows’ rasterising software produces
extremely good results with a few built-in TrueType fonts, but
sub-optimal results with 99% of other typefaces. The Mac OS Quartz
technology ignores font hinting completely and renders all fonts
equally well regardless of their font format.
However, that doesn't mean that font hinting is bad. It's just that Apple is rendering their fonts in a different way.
Also take a look at this
It does help even on larger resolution displays especially when rendering really small fonts.