Otherwise with adjective + noun

The three are very similar in construct and interpretation.

In an interview, he said the idea shouldn’t be that shocking. As long as exchanges are carefully regulated, no one would be forced into it. It (would solve an otherwise intractable problem = is the only way of solving a problem that could not be tackled in any other way.)

Excessive wealth is providing fuel for (an otherwise impoverished industry = an impoverished industry that has little or no other source of fuel).

As far as anybody knows, the Albanians have always been there. The Albanians (speak an otherwise extinct Indo- European language = are the only people to speak an Indo-European language that would be extinct unless they spoke it).

OED

2. attributive. That would otherwise exist without qualification.

1602 W. Watson Decacordon Ten Quodlibeticall Questions 51 At the table above all others their otherwise equals.

1892 D.A. Clarke in A. E. Lee Hist. Columbus II. 650 Stone crosses..give a decided relief to their otherwise dullness.

1992 B. Coote Trade Trap vi. 68 The income they earn from it is likely to be their only source of cash to supplement their otherwise subsistence economy.

Otherwise refers back to, and contrasts by negation, the theme of the preceding clause.

In an interview, he said the idea shouldn’t be that shocking. As long as exchanges are carefully regulated, no one would be forced into it. It would solve a problem that is, without other ways/methods/sources than those mentioned, intractable.

Excessive wealth is providing fuel for an industry that is, without other ways/methods/sources than those mentioned, impoverished. Like fossils fuels, it’s bound to peter out at some point. In the meantime, let them eat cake.

As far as anybody knows, the Albanians have always been there. The Albanians speak an Indo- European language that is, without other sources/speakers than those mentioned, extinct. There is absolutely no native culture - no literature, no art, no music.