There are plenty of reasonable definitions of religion that would apply to atheism, but even that aside, it's a-theism, not a-religionism, it's a rejection of theism, and while many atheists do come at the topic from a generic anti-religion angle, there are many atheistic religions, like The Satanic Temple, who are doing fantastic legal work as a officially recognized religion to fight the current right wing legal nastiness like the abortion ban in Texas by arguing they have religious freedom to preform abortions.

So you're right in the strictest sense that the philosophy of atheism is not de-facto a religion, but next tmme I would recommend making an actual argument rather than incoherent swearing at someone with a mildly spicy take, you're making us all look bad.

Depends on context. In regards to a lot of Federal discrimination legislation like that in Canada, atheism is actively protected under the subheading of "religious belief".

In some Provincial discrimination legislation it is covered by the term "creed" rather than religion but if something goes to the level of the Federal Supreme Court then for purposes of protection against discrimination or for matters of hate speech atheism is considered for all purposes legally a religious belief.

Linguistically laws often term Atheism more broadly as a set of spiritual beliefs. Believing entirely in the absence of the supernatural is still describing what you believe about spiritual matters. Atheism is not a complete absence of belief. You still have things you believe about spirits - you believe they do not exist. If you truly had no spiritual beliefs you would have to be completely unaware that the concept of the belief of the spiritual exists at all including disbelief in the spiritual.

Fundamentally law that applies atheism as a religion employs this logic despite religion having connotation of an internal dogma - something absent in atheism.

You're sounding rather manic here. Relax, the evangelicals are not coming to get you.

I personally would prefer it if we could shake off the last vestiges of christocentrism in our culture - the predominance of their national holidays, their stranglehold on government and taking away women's and lgbtq rights, and even the documenting of history based on bc and ad.

But your assertion is illogical because religion is incidental to bigotry, sometimes used as a vehicle for it, but not inherent to it. For example I once worked as an intern for a summer camp owned and operated by a Lutheran church. It was run by a pastor and her wife, and much of their operations were specifically meant for sheltering and supporting lgbtq+ youth. They never once made any attempt to convert me, and only ever made me feel welcomed and accepted for who I was.

One of the core problems with most branches of Christianity, historically, and into today is the idea of religious exclusivism. They hold that the only valid belief is their belief, and everything else is false and must be done away with. This idea that only Christianity was valid is what allowed them to feel justified in the eradication of pagans in ancient Rome, forced conversions in Europe, and the genocides and cultural erasure of indigenous people on Turtle Island.

So for you and other antitheists to say that only atheism is correct and valid, is just another form of religious exclusivism. Clearly you are already calling for the cultural erasure of all these other competing beliefs, just as the Christians in antiquity did. And likewise, state-atheism already has a history of oppression under Mao and Lenin. Are you a tankie too?

As a sidenote, it would be more accurate to say agnosticism, or even agnostic-atheism are nonbeliefs or nonreligions. But the more proselytizing and dogmatic Atheism gets, the more religiony it gets. So yes you are religious, and yes you are hypocritically guilty of the same bigoted religious exclusivism that your oh-so-hated Christian brothers are. You want to be better than them? Then don't be like them. Support a religiously plural world, a world where we can explore belief freely and still respect each other despite, or even because of, differences of worship.