This isn't really true. Chiplets can be used to "break apart" what would traditionally be one chip, but also to more tightly integrate things that would previously have been discrete components on the motherboard and to use the right process for given a functionality.

Consider AMD's approach. They use multiple CPU dies in a single package to build very high core count systems that would previously have required multiple sockets. Bringing these into one package can make communication more energy-efficient and faster. They also use different processes for different dies. The "IO die" is fabricated on a slightly old process as it is not performance-critical while the best process is reserved for building cores.