I think people sometimes forget that mum's sleep matters too. Chronic sleep deprivation isn't just being tired. t's linked to higher rates of postpartum depression and anxiety, poorer mental health, and even safety issues from sheer exhaustion.
We've had two very different experiences. With one child, we sleep trained once they were old enough. We'd make sure every need was met, put them to bed, when they cried we went in, give them a little pat on the back, say, "Mummy and Daddy love you," and would repeat. It took two nights. After that they slept through (apart from when they were ill or genuinely needed us). If they cried after that, we could usually tell the difference between them briefly waking between sleep cycles and actually needing our help.
Our other child was completely different. We had them on a consistent feeding and sleep routine from birth, and they started sleeping through on their own at just a few weeks old. No formal sleep training needed.
So I don't think there's one "right" way. Every child is different. But I do think parents should be able to choose an approach that works for their family without being made to feel guilty. A well-rested parent is a more patient, present parent, and that's good for children too.