Why is the Crescent & Star on so many Muslim Flags?

Another question on the problem with the Crescent and Star came from a viewer known as 'Truth Seeker', who stated, "I’m a Muslim, and the crescent is not Islamic symbol and it’s not of Islamic origin. What Jay Smith is saying is true. This video is informative and was to the subject. While seeing a lot of comments it seems a lot of non-Muslims and maybe Muslims thought it was Islamic, which is understandable since it was used by some Muslim countries in the last century. But it has nothing to do with Islam. The usage and adaptation is due to the country itself, and their own needs. Saying Islam took it is also wrong. The crescent is adapted by non-Muslims to identify Muslims but was not accepted for a long time (not until 1844 AD), and then was adapted by some Muslim countries [in the 20th century). This doesn’t make it Islamic either, because it simply does not have any religious significance, and Muslims should be encouraged not to use it." This is indeed an understandable mistake by Muslims and non-Muslims alike; namely, the Crescent and Star have nothing really to do with Islam, and this we now know because the coins from the 7th century clearly show that the Crescent and Star is a Sassanian, Persian symbol. But that then 'begs the question'; namely, what is the true Islamic symbol? Christians have a cross as their symbol because it has enormous significance to us, since it was on the cross that our Lord Jesus died, and it is because of the cross that we can have salvation. But it's not just Christians who have important symbols to represent them. The Hindus have the Om sign, used as a mystic syllable, considered the most sacred mantra by Hindus. Buddhists employ the 8-spoked DharmaChakra wheel to signify the eight-fold path to enlightenment, while the Jews have the star of David as their symbol. However, not to be left out, isn't the Crescent and Star now the symbol of Islam? If not, then why have so many Muslim countries put the Crescent and Star on many of their flag? Furthermore, what religious meaning does it have? There is nothing of any religious significance written about the Crescent and Star in the Qur'an, nor in the later Islamic Traditions; so, why has it now been adopted since the 19th century as Islam's universal symbol? If it's merely political, then why don't Muslims say so, and tell us what exactly does it signify politically? Over to you Muslims... © Pfander Centre for Apologetics - US, 2020 (26,770)