I've lived in Sydney for over two decades now and in the past few years, I've noticed the trend of less people keeping to the left while walking.
Obviously, we drive on the left side of the road and many places also have shared bike and foot paths that instruct you to keep to the left side. I believe many who have grown up here would have been conditioned to follow this convention even on unmarked foot paths. Despite this, Australia is very multicultural and many of the big cities are big tourist destinations for people who would normally follow the convention of walking on the right side in their home country.
I personally like having the convention as it generally improves walking efficiency by a lot but lately it almost seems impossible to do so without finding someone walking against the convention. I've noticed even people who I would assume are local are following the convention less.
Do you keep to the left?
I generally keep to the left because that's what I was taught at school and I agree that it makes the flow better if everyone did that.
But I understand that sometimes people walk on the right because that's what they're taught (especially those who have grown up in other countries). When I go to other countries, I walk on the side that most other people do.
There's no right or wrong so it's just a matter of common courtesy. I stay off my phone when I'm walking to avoid potentially bumping into people.