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You are correct in that it would take an extremely high voltage to go from cut-off directly to saturation. But you never go directly there; you have to go through the ohmic region first. While this transition is happening, you are starting to get some Id flowing, which will reduce the Vds voltage drop. This is then going to require less of an increase in Vgs to reduce Rds even further, and also why the Vgs to Rds graphs are curves.
No, you want ohmic region for switching. The many responses on this thread should make that clear.
For your motor, using 10V on the gate should be sufficient to drive your fet into the desired ohmic region. Once current starts flowing, Drain voltage will drop quickly to a much lower voltage. You will no longer have 30V across the motor, as there will be a very small drop across the fet channel's resistance, but the motor voltage should be very close to 30V, and the fet's collector voltage will be less than 1V.
Move left. Higher Vgs
I bet you always use the recommended brand of soap powder in your washing machine and drive your car at recommended 29.99 mph in a 30 mph zone whatever the situation!why not use the recommended gate-source voltage of 10V?
This needs to be done intelligently. Using a 100A MOSFET so you can get away with 5V Vgs at 1A Id (your example) is rarely economical.Taken to extreme, if you always register all the worst case interpretations of all the worst case parameters simultaneously, you end up with a design that's too expensive to build, an aeroplane that's too heavy to take off, and a manufactured product that's not competitive in the marketplace!! If you don't cut costs, your competitors will!
Using a 100A MOSFET so you can get away with 5V Vgs at 1A Id (your example) is rarely economical.