That's a pretty disingenuous presentation of Walmart's profit. The margin matters little when referring to them as a very profitable company. They reported $3.6 billion in their most recent quarter[0]. I'm unsure of what kind of world we're living in when $3.6 billion in profit is not very profitable. The prior quarter was $3.8 billion in profit. And another $3.7 billion in Q1 2019.

So ... $11.1 billion in profit so far this year. Sounds very profitable to me.

[0]: https://ycharts.com/companies/WMT/net_income