On a basic level?
My DD is 17 months now and doesn’t. For example won’t hold a phone to her ear, things like that.
I thought she might be able to stack a few blocks by now too? But nothing. Suppose that’s not imaginary play though.
I have a 5 year old but he has profound autism so not a useful guide as he has never ever used imaginary play
She can’t walk yet but I’m not concerned as she climbs a lot and crawls everywhere. My DS walked at 8 months and is profoundly autistic so not a great indicator all the time anyway