That's a load-bearing "as long as".
Animal welfare laws don't give atheist butchers the option to be cruel. They're required to stun the animal first. Why give halal/kosher butchers the option to be cruel? Especially if you claim "most do" choose to stun.
Be kinder to animals, change "most do" to "all do" by removing the religious exception.
...and then come the progressive types to defend 1000+ year old ritual slaughter customs.
In the US at least, freedom of religion does grant some exceptions. The Amish do not participate in Social Security and Medicare, for instance, but I cannot opt out. I’m not sure how it works other places.
I’m not saying I endorse this, but that is why.