No. About 16 wide spaced ones is enough to cover just about any terrain. Use this
http://www.bikecalc.com/speed_at_cadence to calculate what you need depending on your terrain.
My own personal ideal setup for a 28" wheel bike (Number Two for example) would be the Sunrace 8 speed 11-40 with 28-44 chainrings giving a range of 20 to 114 gear inches.
My choice is conservative for an e-bike because I need low gears to get home in case of battery failure in the last 5 km. The top gear is calculated to spin out at about 50 km/h at cadence, over that speed you need to be rolled up into a ball to stay out of the wind... Number Two has a record top speed of 62 km/h with me making myself as tiny as possible but you can't pedal when you are in that position anyway. 47-52 km/ are everyday downhill top speeds.