Here’s the nuance, Paul says if you’re divorced you must remain “unmarried or be reconciled” 1 Cor. 7
Now take it in the cultural context of the time it was written. Depending on what was the motivating factor for the divorce, remarriage could be completely acceptable - if the covenant was broken by say, sexual unfaithfulness (which is open for interpretation - could be an affair, could be heavy pron use, could be an emotional affair) on the part of the husband, as that shatters covenant obligations.
1 Corinthians 7:15 is specifically legal covenant language, "not bound in such cases"; the phrase “not bound” (οὐ δεδούλωται) is legal covenant language. Historically, “Not bound” meant free to remarry. There is no evidence that it meant “free but celibate forever”. If Paul meant “separated but still prohibited from remarriage,” he had language for that. He used it earlier in the chapter. He deliberately does not use it here.
Paul outlines categories, not blanket rules.
Even strict early church writers allowed remarriage after death, often allowed it after abandonment, and frequently debated adultery cases, which proves it was not settled as absolute. If remarriage were absolutely forbidden in all cases, there would be no debates, there would be no categories, there would be no need for Paul’s distinctions.
The Bible never says “all remarriage is adultery”, “a marriage covenant can never be broken”, “a victim of covenant betrayal must remain bound forever”. Those claims are theological extrapolations, not scriptural statements. Mostly by men who want to treat women as property or are upset they weren't a fit husband and their wife left.