Since current can be calculated as $I = q/t$, the original definition of 1 Coulomb in SI unit system was that it is such amount of charge which flows through wire cross-section having current of $1 A$ in $1 s$ of duration, i.e. $$\tag 1 1C=1A\cdot 1s$$.
Now it is simply stated that $1 C \approx 6~241~509~074~460~762~607.776~e$ (or exact scientific notation).
Now here comes my question,- Why definition of SI unit of charge was moved from that one related to current strength ?
Can it be because time is not Lorentz invariant under inertial reference frame,- i.e. time flow depends on what observer you choose as a reference frame (because it depends on object speed), hence different observers can measure different charge amount(s) flowing in same wires as per (1),- because 1 second unit is there. Hence (1) definition is faulty because charge is absolute quantity and cannot depend on a reference frame. Is that correct or there are other reasons why $1C$ original mapping was abandoned ?
From wiki:
The SI defines the coulomb by taking the value of the elementary charge e to be $1.602176634×10^{−19} C$, but was previously defined in terms of the force between two wires
Best Answer
Because the new standard is more accurate and stable than the previous standard.
No. There was nothing faulty about the previous standard. This one is just more accurate and stable.