The relationship between chain lube and pedaling smoothness is indeed a direct correlation. However, it's not just about slapping any old lube on your chain and calling it a day. There are most certainly other factors at play.
For starters, the type of lube you use matters. A lot. Wax-based lubes, for example, tend to last longer and create less build-up on your chain, which can lead to smoother pedaling and less wear and tear on your drivetrain. On the other hand, oil-based lubes can attract more dirt and grime, which can lead to increased friction and a rougher pedal stroke.
As for specific lubrication techniques, it's important to apply the lube evenly across the entire chain, and to wipe off any excess after giving it a few revolutions. This will help ensure that the lube gets into all the nooks and crannies of the chain, without creating a messy, gunky build-up.
And how often should you be reapplying lube, you ask? Well, that depends on how often you ride, and in what conditions. If you're riding in dry, dusty conditions, you might need to reapply lube every few rides. But if you're riding in wet, muddy conditions, you might need to reapply after every ride. Neglecting regular lubrication can lead to increased wear and tear on your drivetrain, as well as a rougher, less efficient pedal stroke.
So, to sum up, it's not enough to just use any old lube and call it a day. You need to use the right lube, applied in the right way, and maintained on a regular basis. Anything less, and you're doing your bike (and your legs) a disservice.