In addition to situational and contextual analysis, "The skill of the craftsperson was no longer needed" is linguistically analyzed as showing effect. There will always be some predisposing circumstance/action/condition that causes the thing in question (e.g., skill of the craftsperson) to be not needed/needed.
An alternate sentence that shows this, in abbreviated form, might be, "Since preceding factor X is true, then the skill was no longer needed/would be no longer needed/is needed." Or an alternate sentence might be, "The skill was no longer needed/would be no longer needed/is needed because of preceding factor X." Or it might be, "The skill was no longer needed/would be no longer needed/is needed, therefore secondary factor Q has or has not/may or may not occur. ... Oh, and the skill was/would be no longer needed/is needed because of preceding factor X."
In any syntactical construction, the skill being no longer needed/needed follows a cause and is therefore the effect even though it might also become the cause of a secondary or corollary effect branching out from the first effect, which is the skill not being/being needed. Does this make sense? In short: This sentence indicates an effect following a cause but it may also double as a secondary/corollary cause to a secondary/corollary effect.
In addition, the verb is constructed in the passive voice [be + past participle (was + negator + needed)]. Passive voice indicates that the sentence is the effect of some cause, though the instigator and causative action are not mentioned.