Of the two dichotomous noun homonyms 'pledge', below I ask only about that derived from Latin. For the homonym derived from Proto-Germanic , please see this.
[Etymonline for 'plight (n.1)' ] "condition or state (usually bad)," late 12c., "danger, harm, strife," from Anglo-French plit, pleit, Old French pleit, ploit "condition" (13c.), originally "way of folding," from Vulgar Latin plictum, from Latin plicitum, neuter past participle of Latin *plicare "to fold, lay" (see ply (v.1)). [I asked about 'ply' here]
Originally in neutral sense (as in modern French en bon plit "in good condition"),
sense of "harmful state" (and current spelling) probably is from convergence and confusion with plight (n.2)
via notion of "entangling risk, pledge or promise with great risk to the pledger."
Please help me dig deeper than the definition, which I already understand and so ask NOT about. I heed the Etymological Fallacy, but what are some right ways of interpreting the etymology, to make it feel reasonable and intuitive? I don’t quote the brusque OED’s entry.
Particularly, how does a "way of folding" (which sounds limited to folding clothes) generalise to mean (ANY) condition or state ? This question isn't answered by Etymonline, whose last para explains only the imputation of the negative connotation on the noun.