When did I say having more RAM increased memory bandwidth? Are you having a separate conversation with yourself right now? I feel like you might have misinterpreted what I originally said and just ran with it.
There is a lot of misleading information about Apple's unified memory out there so I mentioned it just to be clear.
Having more RAM doesn't increase memory bandwidth and having more memory bandwidth doesn't necessarily mean better performance. You aren't even able to make use of all of the bandwidth your M1 is capable of in the real world [1].
Apple Silicon has good perf/watt but the gap probably isn't as big as you're thinking.
[1] https://www.anandtech.com/show/17024/apple-m1-max-performanc...