Why is an "Ampere [Amp.]" (the unit of electric current) generally too large for most everyday items we use? Why didn't we make the base unit for current something more appropriately sized and smaller to begin with?

The size of the ampere was chosen for convenience and compatibility with Mass Kilogram and Seconds system of units

Explanation:

The ampere which is the unit of electric current is an indication of the quantity of electric charges flowing in an electric circuit per unit time

The unit of the flowing charges measured in ampere is the coulomb

1 coulomb = 6.241 * 10¹⁸ unit of charges

Therefore;

1 unit of electric charge = 1.602 * 10⁻¹⁹ C

Hence;

1 A = 1 C/s

Before 2019 the ampere was defined as the current that will produce a force of 2 * 10⁻⁷N/m between two parallel and straight that are separated 1 meter apart

The size of the ampere was chosen so that the size of the base unit of the ampere in the Mass, Kilogram, Second, (MKS) system would be appropriate.