The thing is, in practice, this hasn't been true since 1985. Nobody actually uses the legacy instructions that are "decoded into RISC-like microops" except people writing 4K demos. In reality, ARM instructions are actually longer on average, and more complex on average. Nor is this a bad thing: it means that ARM IPC is more valuable than x86 IPC.

ARM's advantage is that their instructions are longer, more complex, and easier to decode: not that they're "simpler and more RISC-like". RISC, at least in its original sense, is as dead as a doornail.