Patches for Solaris - CPU's

Does anyone know if the Solaris Critical Patch Updates are cumulative ?
My knowledge of Solaris patching is not good. When patching a Solaris server with the latest CPU, I would have expected the older CPU’s to be no longer relevant.
Is this expected behaviour ?

Based on this article from oracle, the CPU’s are cumulative -

"2.5 Are previously-released security fixes included in the Critical Patch Update?

As much as possible, Oracle tries to make Critical Patch Updates cumulative; that is each Critical Patch Update contains the security fixes from all previous Critical Patch Updates. In practical terms, for those products that receive cumulative fixes, the latest Critical Patch Update is the only one that needs to be applied when solely using these products, as it contains all required fixes"

@BaiYunfei Why aren’t the Solaris patches following the same cumulative/supersedence logic as the Windows patches ?

@BaiYunfei PMR opened - TS000135084