Been There, Done That.
Another Situation Can Cause “Weak” Brakes (More Pedal Pressure Required For Inadequate Results).
If calipers cannot move laterally on their slides/pins then they apply braking pressure mainly through the piston-side pad instead of the pressure being more equal between the inboard and outboard pads.
I live in a rust-belt area and I’ve experienced this myself. Some cars, by design, have a bigger problem with calipers and corroded slides/pins than others. I don’t have as much trouble with all My GM cars, as they have stainless steel covers on the sliding portion of the caliper carriers.
My Chyrsler vehicles don’t have this feature (they’re iron on iron) and are more likely to develop “weak brakes,” especially if they’re parked for a period of days/weeks.
An indication that this is taking place is that the piston-side pads will wear much faster than the pads that are fixed to the calipers.
One needs to spend time thoroughly cleaning all brake components and applying grease water-resitant, heat-resistant greas, liberally, when doing brakes. Also, new pins and whatever other hardware needed should be used.