"Duplication is less expensive than bad abstraction" I think describes just a metric ton of waste I see not just in modern languages but in tons of other applic

"Duplication is less expensive than bad abstraction" I think describes just a metric ton of waste I see not just in modern languages but in tons of other applications. Some of this is that abstraction is a very hard thing to falsify, or test. How do you know you have a bad abstraction? There's a few bespoke quantifiable tests, but it remains largely an artisanal question, so far as I can see from my humble trench.