Christianity gives a creditable explanation of why other religions exist. Other religions fit into the world view of Christianity.
C. S. Lewis - “I believe in Christianity as I believe that the sun has risen: not only because I see it, but because by it I see everything else.”
Christianity does not make sense to other religions, the claims of Christianity do not fit into their world view.
Rom 1:19-23 NASB20
because that which is known about God is evident within them; for God made it evident to them. For since the creation of the world His invisible attributes, that is, His eternal power and divine nature, have been clearly perceived, being understood by what has been made, so that they are without excuse. For even though they knew God, they did not honor Him as God or give thanks, but they became futile in their reasonings, and their senseless hearts were darkened. Claiming to be wise, they became fools, and they exchanged the glory of the incorruptible God for an image in the form of corruptible mankind, of birds, four-footed animals, and crawling creatures.
Rom 2:14-15 NASB20
For when Gentiles who do not have the Law instinctively perform the [requirements] of the Law, these, though not having the Law, are a law to themselves, in that they show the work of the Law written in their hearts, their conscience testifying and their thoughts alternately accusing or else defending them,
Jesus Christ is the absolutely unique gold standard of why Christianity is better than all other religions. No other religion has anyone comparable to Jesus Christ. He was in the beginning with God, and he was God (John 1:1). He took on a human nature, and entered real history. See Luke 3:1-2, which contains real names of people that are known from outside the bible.
Christianity is better because those historical realities were written down by eyewitnesses and and those who knew them, and there are 1000's more manuscripts and fragments of these writings from more places and from earlier than any other historical work of similar antiquity.
Christianity is better because the path of salvation it presents is absolutely unique in the world, and it offers the only hope of eternal happiness to sinners who know they don't deserve it.
John Piper - Why Is Christianity the Best Religion?