Actually, i'd argue strength is party a skill (CNS learning) and partly muscular adaptation, at least in so far as strength is measured in the ability to perform an exercise with a given weight.
Arguably at professional levels, the CNS patterns are near perfect and thus strength gains are almost purely muscular adaptation and very small improvements in technique whereas a beginners strength gains are likely more technique and CNS learning movement patterns than muscular fiber gain.
My uneducated 2c anyway since it's my thread