I've benchmarked ARM systems vs other processors.
On my workload, using Intel as a baseline. AMD under performs relative to standard benchmarks. ARM over performs relative to standard benchmarks. I have seen good performance from Ampere, particularly for the price.
However, ARM architecture complicates my workflow significantly. I've found that they are not worth using it right now due to compatibility issues, easier to just stick with x86 for most things. Dealing with required missing packages just kills the value.
My system isn't generally compute limited anyway. IOPS and egress dominate rather than MIPS.