The article I read (maybe it was US only) said their sales are about $300B and they are being ripped off for about $3B. 1%
Which, likely drives up prices and is not insignificant, unlike your contention.
[urlhttps://www.forbes.com/sites/shelleykohan/2021/02/18/walmart-revenue-hits-559-billion-for-fiscal-year-2020/?sh=4cdf45583358]WalMart Revenue hits $559 billion for fiscal year 2020
[/url]
For a company with that kind of revenue, $3B
is insignificant. There's no reason for them to raise prices and pass it on to consumers except pure greed.