US and Canadian carriers definitely still tell you to put your phone in airplane mode.

They do, but they also frequently offer in-plane WiFi so it's clear they're expecting you to know to turn your WiFi chip back on even though the phone is in Airplane mode.

IIRC the "put your phone in airplane mode" rule is a FAA mandate. Airlines can't change it.

I also wonder what percentage of phones actually get put in airplane mode. I don't think I'd bet that it's as many as 50%.

IIRC last time I saw a study on this it was pretty high. Well in the 95% range. But there would usually be a phone or two on every 737 or larger sized plane not in airplane mode.

That would somewhat shock me to be honest. I make a genuine effort to turn on airplane mode if only because not doing so drains the battery and I bet I miss at least one in 20 times. I would hope such a study was based on measuring ehat pople did as opposed to what they said they did.