When words or phrases occupy adjacent or overlapping semantic fields, they may begin to interfere with each other in the sense that one contaminates the other, thereby changing usage such that the contaminated version supplants the earlier one.
This has happened recently in the American English catachrestic construction “good-paying job,” which has all but replaced the traditional “well-paying job” (with or without the hyphen). It is a further instance of the usurpation of the adjective/adverb “well” by “good.”
In analyzing how and why this has happened, one must start by comparing the constructions “good job” and “well paid.” The compound adjective “well-paying” is the result of adjectivizing “well paid.” Note that one can say “The job/John is well paid” but not “*The job/John is good paid.” The component “well” is then supplanted by “good,” a result of contamination by “good job.” A good job is now preeminently taken to be a well-paying job: whatever else it may entail, the level of remuneration is primary and is reflected in the change to “good-paying.” So there is an underlying value change that undergirds and motivates the change.
The same may be said of the now ubiquitous “I’m good” for “I’m well” in the speech of persons under a certain age (45?). As possibly in the previous case, “well” is all but avoided when juxtaposed with a human agent because it has been relegated to the meaning field associated with health (cf. the neologism “wellness”). “Feeling good” is evidently not the same as “feeling well” (cf. the difference between “I [don’t]/feel good” and “I [don’t]/feel well). A fillip comes from the extancy of “I don’t feel good about it” but not “*I don’t feel well about it.” Cf. the standard “She paid him well” with the dialectal/nonstandard “She paid him good.”