Why do new pads feel "better" than old pads?

The effect changing pads (like for like), even while quite a bit of friction material remains on the discarded ones, is quite often described by drivers as generating an noticeable improvement in their braking experience. What are the factors that give rise to this kind of reaction? For example, is it quite common for the frictional properties of pads to reduce/degrade as they go through multiple heat cycles? Or perhaps it's something to do with the ability of a larger mass of brake pad material when new to dissipate heat faster/more efficiently? Grateful for any thoughts on this.

Pads might be overheating a "glazing", and new pad is not glazed yet? What if you remove the pads, scuff them on a belt sander and re-install. is the performance better, worse or the same?

Also, I would look for any mechanical issues - like burrs on the sliding surface that are preventing the pad from moving freely, or pad taper wear.

As David said,and pads may be tapered which will affect the contact pressures, the additional thickness may be reducing the heat transfer to the fluid, etc. Depending on the application, the brake fluid may be flushed with fresh, which is another variable?

But it also depends on what the driver(s) consider an improvement?

Thanks for the responses.

The points made about potential tapering, glazing etc could/would of course have a bearing on matters but I don't believe were commonly valid across the multiple cases I've come across. Most of these were encountered with Pagid RS14 pads in identical 4 pot AP entry level calipers on one particular make and model of performance car. The pads themselves worked extremely well, but performance dropped off noticeably as the friction material wore to around half or less-which wasn't very long because the pads started out at only 14mm total thickness!

I could accept an explanation that said that the properties of the friction material must changed after a certain amount of usage involving multiple heat cycles etc, but how likely of common might that be, especially with a premium pad such as the RS14? And surely that's exactly the exactly the kind of thing that a manufacturer would strive to avoid see happening?