Yes, there would be a bit of enchantment removal here and there, but most of that was in the sideboard and never really added many counters
To make the discount worthwhile, you need to have this apply to almost all your other cards and then cast a flurry of spells in the same turn
Cards like Mishra's Bauble, Chromatic Star, and Currency Converter flood the board with cheap artifacts to fuel cards like Thought Monitor, Kappa Cannoneer, and Urza, Lord High Artificer
If we basically just mash all the different builds of Deaths Shadow together without cutting anything, I can imagine that it might be the best build
Elspeth, Storm Slayer's static ability is a doubling card (Mark Rosewater's favorite), so there's no doubt this Planeswalker will be one of the most valuable cards from the set