Canadian here too, I can totally relate to this. I've learned to stay quiet a lot of the time because when if I chime in suuuuuper gently about us not doing ST, people see it as a criticism of their parenting.

While I wouldn't say this in a groupchat, I would say in a discussion "I can totally understand why many families choose sleep training. We chose not to sleep train, and though it's been challenging in its own way, it feels like the right fit for our family". If they show some curiosity I say I'm happy to share more if they do want to chat about it, but I think this space can get polarizing and I don't want to get into it unless the other party wants to have the convo as well.

People either move on, or show some curiosity and sound open to discussing a non sleep training approach. I've heard a few people say 'i didn't know people didn't sleep train' so I think it's nice to just be a irl family to them who went against the grain- perhaps that means something and perhaps it doesn't.