Going to 3 bullets for close range would mean that both, long and short distance, the deagle will be almost unusable bcz of 2 reasons:
1- There are weapons that do way better at close range already (Cz, tec-9, five-seven).
2- The deagle already kills with 3 shots when you are at mid-long range so you are almost in all situations forced to be able to 1 tap kill.
So basically saying that it needs 3 shots to kill at close range, means that you want to kill a weapon that already is in a disadvantage at close range. There way more situations where deagle vs AK at close range ends up with ak winning than the other way around, if u don't believe so, then u should watch the latest games where even when the deagle is "abused" based on some stupid comments, they don't win rounds. The only teams who are capable of winning eco rounds with deagles are FaZe, G2, Vitality with zywoo and NaVi with simple, the rest usually depends on the situation.