First of all, it's the last Apple OS that received 8 point updates--Tiger got 11 (lately, the most we can hope four is maybe 5), and before Apple started rushing out OS versions once a year, without ever really getting them completely polished. Second, and maybe most important, it's the last OS that isn't a bastardized mix of iOS and OS X. But, yes it's no longer supported, which is why I'm running 10.8.5, which is very likely to see its EOL in the fall, when 10.11 arrives--and when I will probably jump off to 10.9, for which I kept the installer. I still have Snow available for dual booting for when I need an older PPC app.
Booted to Snow, I don't use Mail, or any application that uses WebKit, such as Safari, which is very badly outdated and not safe.