The Mangekyo Sharingan had a far bigger role to play after the anime's time skip in the Naruto Shippuden era, especially since the power levels were rising higher than ever.

In addition to why the Copy Ninja lost his Sharingan in Naruto, another question is if Kakashi ever got his Sharingan back. As suggested in the earlier paragraphs, the answer is no.

In Naruto, Kekkei Genkais are a special gift passed down to individual ninjas in certain clans. For the Uchiha, the Sharingan defines them as a unique group.

In the series Naruto, the Uchiha clan is a particular group of ninja, famously known for their visual prowess. The Uchiha are famed for possessing the Sharingan, a dojutsu kekke genkai.