Yes, they also make this mistake. The frequencies correspond to the numbers being summed, so if the numbers are huge (>100 bits) the frequencies will be so high

Yes, they also make this mistake. The frequencies correspond to the numbers being summed, so if the numbers are huge (>100 bits) the frequencies will be so high that the wavelengths would be smaller than atoms, where you can't construct physical circuits. If you scale down the frequencies, the time it takes for a complete period goes up exponentially with the number of bits in the numbers.