In regards to the headline question "Is it humanities downfall?"
I don't really see how it could be? Religions give a lot of people comfort and meaning in their lives and a lot of them are moderate believers, that can make science and religion work together. As for Richard Dawkins, which I have watched a lot of debates with, he is very open about being against religious teachings, but I don't think he is against all of it, he is primarily focusing on religious extremists from the angle of education and humanism.
Meaning that certain religious views, which push the ideas that for instance the Earth is around 6000-10000 year old. That creationism should be taught as an alternative to evolution etc.
I don't think that he cares to much about peoples personal beliefs as long as they don't impact human lives.
Teaching young children that if they don't behave in a certain way, that they will go to hell for an eternity and burn and suffer, I do agree with him, is on the border of child abuse. Children are extremely acceptable for things they are told, especially by their parents and telling them these things, which in no way have been verified as being true, is to terrorize children.
Pushing for knowledge that can be verified and explained and teaching people this is not a negative thing, but is something that should be encourage. Science in the last many years is what have heighten our well being the most, from everything to better living conditions, better healthcare, the ability to feed ourselves, to learn about our planet, about the Universe etc.
Humanity as we know faces a lot of issues, whether its climate change, hunger, wars, pandemics and what else might hit us in the future. And so far, science and knowledge is essentially our only solution to these problems and even that might not be enough.
We can't live in a world and expect things to work out, if people simply believe whatever they want to because it feels right. We can't overcome Covid or climate change by praying to God or by thinking that he will protect us. That is the path of ignorance, there is no verified data that this would work or ever have worked. And if that is the case, we have to rely on ourselves and we can't do that, if around half the people just believe whatever they want to and have no respect for the knowledge and discoveries that are made.
Religions have had so many years to provide evidence for the divine, to demonstrate that divine intervention is true and can solve things. Yet, they have nothing to show for it. Nothing to rely on that can solve the issues we face.
So on one side we have people like Richard Dawkins and the others you mentioned, that pushes for secularism as the best way forward, that we have to focus on knowledge based on critical thinking and rationality, because it has demonstrated that it works. And on the other side, you have religious people that feel stepped on and violated, because their religions are not seen as part of the solution.
This is not ultimately about religion itself, its about how we approach things and issues we face. If the varies religions can get the God they believe in to help, these "new" atheists wouldn't care, but again, none of the religions have even remotely been able to demonstrate or been able to get help from their God(s).
So to get back to the question of the headline.. "Is it humanities downfall?" the answer to me is no. It might in fact be our only option. We have no other ways of dealing with issue than approach them with the knowledge we have and which can be demonstrated to work.
We can't keep refusing knowledge that contradict religious beliefs, and if they do, the religious people are perfectly free to demonstrate that they are correct.
Just a fun video of Richard Dawkins getting love letters from religious people:
