In truth, the Cyrillic alphabet has very little of the Glagolitic alphabet and a lot of the Greek alphabet. I would say the work of the disciples of the brothers is more a tribute to their teachers than they really relied on the works of Cyril.
Discussion
Can't disagree with that.
It's an interesting fact that in the 20th century, many countries abandoned the Cyrillic alphabet. The Soviet Union even developed a project to switch to the Latin alphabet. However, Stalin refused to implement it at the time. Had it not been for Stalin, perhaps Cyrillic in this time would have suffered the same fate as Glagolitic.
Oh yes, we have Latin alphabet in Serbia.