The reason MOSFETs are preferred over bipolar junction transistors (BJTs) is because the gate (base) current is negligible in MOSFETs compared to BJTs. You "waste" base (gate) current in BJTs to gain control over the collector (drain) current. But, in case of MOSFETs, you don't have to sacrifice gate (base) current to have that control.
Complementary MOS (CMOS) takes that concept even further and makes the drain current zero in steady DC state.
Because of these properties, MOS transistors have driven BJTs out of existence from electronic circuits, practically speaking.
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