I think you're talking about ASICBOOST, more importantly the "Covert ASICBOOST" drama, which was almost entirely fabricated as a political ploy to turn the /r/b

I think you're talking about ASICBOOST, more importantly the "Covert ASICBOOST" drama, which was almost entirely fabricated as a political ploy to turn the /r/bitcoin community against the mining community. It was used to justify the soft fork inclusion of SegWit (Segregated Witness) but in reality had zero impact on the actual ASICBOOST capability, which was an overly complicated and incredibly mild hashing optimization which no one really actually used. The risk of orphaning blocks was likely higher than and potential profits from the extra advantage.