“Even atheism is a religion.”
With all due respect, that isn’t going to fly.
Atheism is just lack of “any religion period”. Atheists do not label themselves or consider themselves as a religion. That false label is forced on them by other faiths without their consent.
Why is it someone can’t just “opt out” of all religion period? Zero zip? Simply choose not to go to the party at all?
Same with Buddhism, it is not a religion it is technically an “education”. But other religions falsely label it a religion.