Having analysed their competitors’ offerings in depth, they know that whatever feature or benefit they name, customers could probably find something similar somewhere else.
The thing is, customers generally don’t analyse the various competitors in anywhere near as much depth. They’ll search, or go by word of mouth, and then research the brands they learn about to see whether they fit their needs and values.
What matters is that they can discover enough specific characteristics of the brand to assess that fit. If the fit is good, it won’t matter if one or other of those characteristics is similar to the competition; once they’ve found what they’re looking for, potential customers are unlikely to go fact-checking to make sure the brand’s characteristics are genuinely unique. They are likely to look elsewhere if they don’t find any specific characteristics to latch onto.
So from a brand strategy perspective, what matters is not that you offer something no other brand can replicate. What matters is clear, confident commitment to a position.