This will mean they enter with extra +1/+1 counters when they are creatures, and charge counters when they arent
While most enchantments wont outright kill a player as quickly as big creature threats can, they make up for it with resilience to common removal and sheer oppressive impact
A well-drafted deck with an appropriate sideboard can alleviate this problem, but in most scenarios, you don't want to include cards like Disenchant in your main deck unless you are certain that you are playing in an artifact and enchantment heavy meta
Each joke you tell should be appropriate for the audience, keeping in mind that not everyone in attendance may be aware of your personal comedic stylings
So, WotC did do a solid job of crafting these decks to keep the action moving, preventing too much turtling and one player from just crushing everyone else
Sometimes you need a little extra push from a mill deck to get rid of the last few cards in a players library, or maybe you just want to draw a few cards at the end of an opponents turn