I guess I would add that it may only be a Salient as it is with respect to certain things like flights, because there are a couple of outstanding counter examples like cell phones and and automobiles which seem to exhibit the exact opposite trend.
A deeper analysis might reveal that there is a cycle at at work here, wherein the initial novelty of a prodict or service which is destined to become a commodity, means there is not yet a strong set of expectations about what the service or product is "supposed" to provide. distinction in the market has to come from adding context to that essentially commodity utility.
But later on some consumers begin to recognize that some of the additional context may not be strictly necessary or offer a value to them and would prefer compartmentalization of the core product as distinct from its value-added variants.
When flights were a comparative novelty, or at least a novelty in different market segments at different times, distinction between products was through different levels and configurations of service or features rather than price.
This may still be the phase of the product cycle that cell phones (setting aside the fairly stable tiers of product within that category) are in. It's harder to make as direct across the comparison with cars as they are older than both air travel and mobile phones, and because of all the regulation that enforces standardization of non-optional features related to safety.
A simple example would be the hollowing-out of conventional terms everyone believes they hold the same settled definition of, such as "a flight." Instead of transacting according to what consensus suggests "a flight" meant a decade or two ago, when most would have expected this term to have thoroughly matured to the point of semantic stability, instead delivering against the most contextually minimized, stripped down interpretation of the term possible that still qualifies as valid, and attaching fees to all of the other attendant associations of value that used to be included in the scope of general consensus of the term.