This statement is not appropriate, because ceramic substrate is also a branch of printed circuit board. Ceramic substrate, CEM substrate and FR-4 substrate are side by side, and the manufacturing process is not much different, but the supporting materials are different, so there is no saying of replacing the circuit board.
At present, more than 90% of the materials on the market are FR-4, and ceramic substrates account for a small proportion, and will not become the mainstream in the future.