Those of us who have followed the food-retailing industry for a while recall well that just a few years ago it was widely predicted that Walmart Stores’ grocery aisles — increasingly burgeoning with low-priced product — would crush the conventional supermarket business.

It seemed like a safe bet at the time. After all, Walmart bestrode the land like a colossus, hurling down gigantic and food-heavy supercenters in virtually every hamlet that had even a fair amount of population within a 50-mile radius.

More than that, Walmart was building an unassailable low-price bastion by taking full advantage of the built-in inefficiencies endemic in the product-acquisition practices of conventional supermarkets. Walmart did that by eschewing manufacturers’ false funds such as promotional money, slotting allowances and brokerage fees. Instead, Walmart demanded and got dead-net pricing from manufacturers. There was no way conventional supermarkets could immediately reverse-engineer their way out of dependence of those “street monies,” so they were stuck with the high-price-point model. Before long, Walmart captured a majority of consumables sales in the nation. Between 2006 and 2010, Walmart’s grocery sales grew from 39% to 54% of its US revenues, reaching a whopping $140 billion, or almost a third of the US market. That’s a lot of milk and hamburgers.

As a result, during the past decade or so, scores of marginal supermarket chains, independent supermarkets and their wholesalers failed outright or were acquired by larger companies. The most spectacular failure came when the then-largest grocery wholesaler, Fleming Cos., suddenly ceased operation and liquidated. Many surviving retailers downsized and are mere ghosts of their former selves. In that number are A&P, Bi-Lo and Winn-Dixie.

Indeed, many predicted that Walmart and no more than 10 of the best-run conventional chains could possibly survive into the long-term future.

Not so. There are now at least 75 substantially sized supermarket chains and independent operators, many of which are doing pretty well, according to data published by trade publication Supermarket News. They range from Kroger, the nation’s largest conventional supermarket chain with annual sales of $81.1 billion, down to the smallest, a regional independent with annual sales of $93 million.

What happened? Walmart inflicted some wounds on itself, chief among them reducing stockkeeping units of branded goods in favor of a generic-looking private-label range. It also wandered some from its low-price leadership. But the problem is far deeper than those factors: Consumers simply don’t want to shop in supercenters nearly as much as they did before.

Consumers are turning elsewhere — particularly to “small-box” stores — in droves, in fact, as they react to pressures on them concerning time, travel costs, high unemployment, recession and, far from least, because of the aging-population bulge.

In short, consumers have lost their ability and appetite for traveling long distances to shop a time-inefficient cavern of a store. The Walmart advantage once fully evident to consumers is melting away.

Consumers are finding some relief from mounting pressures on them by turning to small-store alternatives such as Aldi, Save-A-Lot and dollar stores. Aldi and Save-A-Lot are fundamentally food-only stores, while dollar stores such as Dollar General and Family Dollar are broadline retailers that are rapidly increasing their food offerings. They’re also now offering well-designed and high-quality private-label food product. About three-quarters of Dollar General’s sales are in consumables, and Family Dollar isn’t far behind.

These small stores offer price points that, surprisingly, are in many instances equal to or slightly below Walmart’s. They are located near large numbers of consumers, often in small strip shopping centers. Those small-store features combine to allow consumers to save time, travel costs and increased purchasing economy. The stores don’t have everything, but are ideal for fill-in shopping or for single-meal planning.

As for conventional supermarkets, they will never again dominate market share as they once did, but they are presenting themselves as attractive alternatives for pantry-filling shopping trips. That owes largely to the fact that, at long last, they have learned how to lower price points so they compare fairly well with Walmart’s. Like survivors of the Middle Age’s black death, supermarkets’ numbers have been whittled, but they’re now a robust lot.

In the future, consumer spending on grocery is likely to continue to drain from Walmart and toward small-box stores, conventional supermarkets and other alternatives, especially if these can keep price points in check. These alternatives can succeed even without matching every Walmart price point dollar-for-dollar. Shoppers will generally tolerate an upside price spread of 8% if they see needed product within arm’s reach. Beyond that, many will decide to look for the product elsewhere.

So the ongoing formula for the success of the non- Walmart universe is clear: Present product shoppers want in an environment they enjoy and at prices within 8% or better than those of competitors.