>>1670057it depends mainly on if you have steep climbs and descents. in flatland you won't need to use most of the gears most of the time. see pic related for how big the jumps are between the gear ratios, the jumps could be even bigger on an entry level groupset. the efficiency loss from being in slightly the wrong gear is not as big as you might think. the optimal cadence also goes up along with your wattage so that the optimal gear ratio doesn't change in direct proportion to the speed you're going. in road bike crits like shown on the trainer road youtube channel they often go up to like 110 rpm when they aren't just cruising. it's also common to prefer a lower cadence on climbs and to push harder on climbs so that you don't necessarily need that low of a gear. you can also train to have a broader power band so that you're not as sensitive to having a certain gear ratio in specific scenarios. you can also cope by having a fixie with a more aggressive riding position (better aero and could improve your power output for shorter rides rather than long endurance rides), better aero, weight, stiffness, more efficient drivetrain, wheel bearings, and overall robustness and low maintenance compared to a similarly priced road bike.
https://myworldfromabicycle.blogspot.com/2012/02/ideal-cadence-for-competitive-bicycling.htmlhttps://www.youtube.com/watch?v=ACnCIhJJupc 