People are read, that is, informed or educated through reading. The OED flags this verb sense of read as obsolete, and the adjectival usage as chiefly predicative, but well-read has become a fixed expression.
1a. Of a person: experienced, versed, or informed in a subject by reading… Used simply and with adverbs; now chiefly in well-read
b. Informed by reading, acquainted with books or literature, learned. Chiefly in predicative use…. Now only with modifying adverbs; chiefly in well-read
Similarly, lived is a perfectly legitimate adjective indicating that something has a certain kind or length of life, but the OED notes it is used chiefly as the second element in compounds. In other words, it's uncommon to describe a life as simply lived (which seems tautological), but it could be long-lived, self-lived, soft-lived, and so on.
There are any number of these fixed expressions; for instance, you wouldn't describe a long-winded person as merely winded if he were briefer, or a long-lasted television show as simply lasted if it only ran for ten episodes. The attribute component of the compound may also be necessary in many cases where the main adjective or participle does have a contemporary meaning; an informed electorate is rather the opposite of an ill-informed electorate, and a high-born woman is equally as born as a low-born woman— in the main sense, if not any others.
Other than that, I see little grammatical difference between being short-staffed and being very tall, or between being hard-earned and being highly taxed.