To make more money, of course. Increasing your sales from 12% of the market to 20% of the market by offering a burger (or whatever) for $4 of pure profit instead of competitor's $6 doesn't stop the gravy train.
Only in idealized markets and even there where consumer demand is elastic. For inelastic products industries raising their prices in unison can all see greater profits because the changes in demand are outweighed by the increase in profits. So much of what we learn of markets are idealized games to make sense of extremely complex emergent systems made of people.
Within the span of a few dollars for many items people will often eat the difference for familiarity and out of habit. I don't know about you but I rarely sit and comparison shop between similar options at the store I grab the thing I'm used to and expect to get because that's the habit and lowest friction.
> Within the span of a few dollars for many items people will often eat the difference for familiarity and out of habit.
Which is exactly my point: either a rival corporation would be able to get market share via undercutting, or price increases are not actually that sensitive to consumer to begin with.
I actually think it’s the opposite—if you notice your usual purchase suddenly goes up 20% it’s very noticeable because you are always buying it. It may cause you to buy an alternative.