Can you elaborate on what you mean by "architectural tradition"? I am not familiar with this term. What is the commonality of all those different architectures?
ARM/Power/MIPS/RISC-V are all examples of a reduced instruction set architecture, RISC.
Basically, despite how sophisticated the CPU of these machines becomes it is still trying to make the appearance of executing instructions in sequence.
Current x86 processors can execute many instructions in parallel under the correct conditions leading to Instructions Per Clock (IPC) greater much than one. However typical IPC hovers around 1 and some change, unless a lot of optimization effort is invested.
In order execution of an instruction sequence (or the appearance to the user of it) is the bottleneck that has led to single threaded CPU speed increases to all but disappear now that CPU frequency scaling has more or less halted.
I think that's all the OP was getting at.
Rather the DEC VAX and perhaps MC68k are poster childs of CISC. For a discussion of RISC vs. CISC see
> http://userpages.umbc.edu/~vijay/mashey.on.risc.html
or its extended version
> http://yarchive.net/comp/risc_definition.html
and look at the tables there. You will see that among the processors on the "CISC side", the Intel i486 is nearer to RISC than many other CISC architectures.