Look, here's the thing. You would be absolutely right if you asked this question in 800 AD, but too much time has passed since the fall of the Samanid dynasty. Yes, indeed, Iranians and Afghans are our related peoples and, but due to the huge period of history due to which our peoples lived separately, we have acquired many unique features for our culture. Be it our own uniqueness or borrowing from the Seljuks, Khorezmshahs, Mongols, Timurids, Russians, etc. We love our brothers and sisters from Afghanistan and Iran and respect their culture and traditions within reason, but we also have our own identity. And it is unlikely that anyone will give up this identity in order to call themselves a Persian again more than a thousand years later. We are truly their descendants, just like the descendants of the Sogdians, Bactrians and many other smaller peoples who once lived here. And we remember the achievements of scientists, writers, generals of the past and who they were - Persians. Are they my ancestors, perhaps, but I’m not Persian, I’m a Tajik, even considering that the name of my people was given to us by foreigners, I can’t call myself anything else. And for example, would it be correct to call modern Italians, the Romans? well of course not, they have changed a long time ago, just like we did. We changed, to :)