The force applied by the tire to the tarmac is determined by the ratio of the crank arm length to the radius of the rear tire, multiplied by the gear ratio. Period. All of this analysis of intermediate forces and torques gets canceled out. Yes, it is true that you are applying more torque to a smaller chainring than to a larger one, but this is exactly canceled out at the rear wheel as the smaller cassette cog applies less torque to the wheel than does the larger one!

One can try this out on a typical road bike by comparing the effort of pedaling a 50/25 gear combo to 34/17 (or something similar depending on your gearing).