It really depends on what your goal is. Usability, keeping a familiar interface, performance, all of that are things that make it reasonable to stay on an outdated OS, and none of these reasons are bad.
Security (which is the only thing we are really talking about here) does require updates.
If security is your most important concern, you need to update. If security is not your biggest concern and other topics are more important for you, it might be reasonable to stay on older versions.
But in the context of this post, which was purely about security, having long term security updates is important.
It really depends on what your goal is. Usability, keeping a familiar interface, performance, all of that are things that make it reasonable to stay on an outdated OS, and none of these reasons are bad.
Security (which is the only thing we are really talking about here) does require updates.
If security is your most important concern, you need to update. If security is not your biggest concern and other topics are more important for you, it might be reasonable to stay on older versions.
But in the context of this post, which was purely about security, having long term security updates is important.