Bias current in the Amplifier branch
I've used this topology ---- constant current source load for bipolar amplifiers ---- to achieve gains of 10,000x (80 dB) in one stage. The output was buffered using a JFET to avoid bias currents.

The "vi" was part of a negative feedback loop, thus "vi" was servo-loop adjusted to hold the gain node near the mid-swing for adequate linearity.

Summary: Fet#1 cannot be operated as constant current.