The problem isn't the sockets. It costs a lot to spec and build new sockets, we wouldn't swap them for no reason.

The problem is that the signals and features that the motherboard and CPU expect are different between generations. We use different sockets on different generations to prevent you plugging in incompatible CPUs.

We used to have cross-generational sockets in the 386 era because the hardware supported it. Motherboards weren't changing so you could just upgrade the CPU. But then the CPUs needed different voltages than before for performance. So we needed a new socket to not blow up your CPU with the wrong voltage.

That's where we are today. Each generation of CPU wants different voltages, power, signals, a specific chipset, etc. Within the same +-1 generation you can swap CPUs because they're electrically compatible.

To have universal CPU sockets, we'd need a universal electrical interface standard, which is too much of a moving target.

AMD would probably love to never have to tool up a new CPU socket. They don't make money on the motherboard you have to buy. But the old motherboards just can't support new CPUs. Thus, new socket.