Operational amplifiers were first designed to use voltage analogies as numbers for addition, subtraction, multiplication, and division operations, and have also become the basic building blocks for analog computers.
From here we can see that the operational amplifier is a voltage calculation device, amplifying voltage is only part of its function. The op amp cannot directly amplify the current like a triode. If you want to amplify the current, you can only change the current into the corresponding voltage signal, and then calculate the processing.