While it's an oversimplification to attribute these gains to a single set or event, the Pokemon Company continues to build momentum with each major announcement, setting a new standard for modern cards
A deck built around proliferate effects, planeswalkers, and counter synergies can go from a slow grind to an explosive turn in a single combat step
(When this equipment enters create a colorless 1/1 Hero creature token and attach this to it.) Equipped creature gets +1/+1, gains "Whenever this creature attacks you gain 1 life," and is a Cleric in addition to its other types
At best, has a few options, but that's it
2) Dividers now support a side cut out
Deadpool's card swapping ability gets miles better if you find a way to create copies of him, which is why we've seen cards like The Master Multiplied, Determined Iteration, and Orthion go up in price