Not really. All the Aztecs weren’t killed. All the NAZIs weren’t killed.
They just have to be crushed. Totally crushed.
And there are still Nazi’s and the ideology is alive.
It is just in abeyance at the moment.
I don’t know about Aztecs but there are many other older pagan religions that are still practiced all over the world, Druids, Zoroastrianism, Native American religions, etc.
There are many places in the Middle East and North Africa where there are pockets of people who never adopted Islam, they kept their older religions, albeit they have to practice them in secret such as the traditional Berber religion practiced today in the Atlas mountains of Morocco. There is Sufism, Bahai, Zoroastrianism, Druze, Yazidi ... many others that pre-date Islam and Christianity that are still practiced. Even Islam could not “wipe out” all of the former practices and beliefs.
I’m sure many die out naturally. But by conquest? I don’t think you can ‘wipe out’ religious or other beliefs totally by this method. Certainly not when your population is so much smaller than theirs.