Historically, Walmart thrived in relatively small town, rural areas. When I was homeless in downtown San Diego, I had to take a bus elsewhere to occasionally visit the Walmart. There aren't any in the downtown area. They don't typically do well in the big city.
You presume people have those options. You presume they can readily and conveniently get to them in a way that makes financial and logistical sense.
In my small town, people who hate Walmart and are happy to drive an hour to a bigger city once a month to "visit the city" and do some of their shopping grudgingly shop at Walmart because it's the only source for a lot of things, even if you are happy to pay more money just to spite Walmart.
People from even smaller towns around us take the bus to shop here (or drive here), mostly at the Walmart. My small town is a regional shopping hub and has shopping and eateries more like a city several times larger because of it. We still can't reasonably get away from shopping at Walmart.
Don't get me wrong. I'm a Walmart fan and wouldn't have moved here if there was no Walmart. I'm just saying I've spoken with a local who hates Walmart and grudgingly does some of their shopping there anyway because they can't always find reasonable alternatives, try though they might.
Historically Walmart drove out all the other shopping in small towns that was barly hanging on as the place locals went when they needed something fast. Until Walmart opened in my town we planned monthly trips to the city an hour away for most of what we needed. The local shops had some things, but the high prices and poor selection meant we couldn't afford to shop local often.
Note that Walmart of then is not the Walmart of today. They used to have quality products at a good price.
'cept Walmart has been raising its corporate minimum wage. Then there's Costco that has always paid a wage about the prevailing for retail. No shortage of price-conscious customers at either.
Everyone was raising wages, so everyone’s prices also went up, and Walmart still likely has the best cheap:convenient ratio. Point is Walmart can’t choose to raise everyone’s wages 6%, unless everyone else does too, because the whole reason people go to Walmart is it’s the cheapest.
Costco targets people with more disposable income, so not exactly a comparable market.