Please understand, this is not how it works. You're making the same mistake as Esmer. Yes, your Dimeritium Shackles "answers" these cards but they put you behind on points, e.g.:
Opponent plays Vrihedd Dragoon, you play Dimeritium Shackles. Now his Dragoon is locked alright, but you're also down four points. You would have been better off using Alzur's Thunder on it, and nobody runs Alzur's Thunder intending to cast it from hand either. You would also be unable to play Shackles if you got the blue coin + the opponent is ahead by 5 points or more after he plays Dragoon.
Opponent plays Archespore, you play Dimeritium Shackles. Now you are down 3 points. If you actually stopped his other cards from being effective this might work (which is why Shackles works against consume, the only deck it works against). But he still has other deathwish units. Yeah he can't use Cyclops on the locked Archespore now, but he can still use it on a Dao or another Archespore.
Playing Dimeritium Shackles will lose you games. This is why nobody uses them at high level.
As for "who the hell plays that deck in the higher elo" - I dunno, 9.4% of people (Brouver is #4 in popularity among all leaders according to the meta report). Also, alchemy doesn't run Dol Blathanna Sentry which is a ST card, you are thinking of Spelltael, and you can't lock those either because by the time they come down they're already fully buffed. And, spy decks don't run False Ciri, heck nobody runs False Ciri.
Opponent plays Vrihedd Dragoon, you play Dimeritium Shackles. Now his Dragoon is locked alright, but you're also down four points. You would have been better off using Alzur's Thunder on it, and nobody runs Alzur's Thunder intending to cast it from hand either. You would also be unable to play Shackles if you got the blue coin + the opponent is ahead by 5 points or more after he plays Dragoon.
Opponent plays Archespore, you play Dimeritium Shackles. Now you are down 3 points. If you actually stopped his other cards from being effective this might work (which is why Shackles works against consume, the only deck it works against). But he still has other deathwish units. Yeah he can't use Cyclops on the locked Archespore now, but he can still use it on a Dao or another Archespore.
Playing Dimeritium Shackles will lose you games. This is why nobody uses them at high level.
As for "who the hell plays that deck in the higher elo" - I dunno, 9.4% of people (Brouver is #4 in popularity among all leaders according to the meta report). Also, alchemy doesn't run Dol Blathanna Sentry which is a ST card, you are thinking of Spelltael, and you can't lock those either because by the time they come down they're already fully buffed. And, spy decks don't run False Ciri, heck nobody runs False Ciri.