Everything to me is interaction with your child.
So "playing" per say... is a really wide thing.
Everything to me, as you interact with your child, is teaching them something and them having fun, hopefully. Thus it is "playing."
Even if they are helping you, wipe the tables. They are "learning" something. Play... is learning. As well.
But for one-on-one "play" it really varies.
Per child and per their rhythms.
My daughter for example, when younger, didn't have anyone to "play" with... because she was an only child. So I spent a lot of time with her throughout the day. But that included me doing things too, along side with her. And teaching her things.
My son, he is more independent and does a lot of self-play. And since he has a sibling, (my older daughter) they play together, too. And are two peas in a pod, even if they are 4 years apart.
I do my day as need be. Which includes time with the kids, directed time and also do things I need to do. Chores. Errands, etc. Therefore, the kids get used to... the runnings of a home and family... and it becomes, just how it is. And they are a PART, of that.
They know, we always do things together, and then there is adult time and just things which we all do together.
My daughter even helps me wash the windows... and for her this is "fun" and together time/playing.
Of which, play time is age appropriate... and per the needs of my children.
In some Era's...the parents did NOT do much one on one "playing" with their kids... because, they were working. And the times were different.
My Husband, his parents did not play with him. He was pretty much on his own. They supervised or so. But he entertained himself, a lot. Even if his Mom was a stay at home Mom.
But he said, it was lonely.
So the bottom line is: you do what YOU feel is best, for your child and their needs.
It is not about how many hours... you spend one on one with them.
Because, quantity does NOT equate, quality... or fulfilling your child's needs... emotionally.
Some adults spend a ton of time with their kids... but they are not present. They are still, not "with" their child.