In most cases, you are paying the extra 2 making it comparable to Disallow
You also have cards like Ugin, the Spirit Dragon and Calamity of the Titans that act as sweepers
If the target permanent is an illegal target by the time Generous Gift tries to resolve, the spell doesn't resolve
Paradox Engine The July 2019 announcement said the most telling thing about Paradox Engine: While we dont ban cards which are only problematic if you build around them, Paradox Engine has clearly demonstrated that it doesnt need to be built around to be broken. We knew we had to ban Paradox Engine despite its popularity
Ashes of the Abhorrent Ashes of the Abhorrent might be too narrow an answer
Coupled with reprints of vital staples like Gyre Sage, Walking Ballista, and Fathom Mage, Counter Blitz has almost everything you could ask from a preconstructed deck