Comment by yabones
The reality is that as great of an interceptor as it was (and possibly the best dedicated interceptor jet ever made), by the time it was ready it was already obsolete. With the introduction of ICBMs, there was simply no need to have jets purpose built for shooting down TU-95's over the Arctic when the new threat was impossible to shoot down.
And yet the reality is that within a very short time after cancelling the Arrow the need for an interceptor was not, as you say, obsolete. That requirement meant that the Canadian government bought ex-USAF CF101-B Voodoo jets to replace the truly obsolescent CF-100 that the Arrow was meant to do. The development of interceptor aircraft similar to the Arrow continued on in various countries for decades.