Whats the verdict on sizing a general purpose CPU to become the basis of a software router? I've no deep knowledge of the field, but my understanding is a lot

Whats the verdict on sizing a general purpose CPU to become the basis of a software router? I've no deep knowledge of the field, but my understanding is a lot of router/switch hardware uses dedicated hardware designs to ensure they deliver the bandwidth and ultra-low latency even if the device is absolutely slammed with traffic. I've read before routing/switching in software like pfsense or similar can potentially struggle under some workloads dedicated hardware does not, but I've never seen a good analysis of the trade offs with actual benchmarks. I'm sure most recent modern CPUs can probably handle a lot, but people often repurpose old SBCs they have like Raspberry Pis etc for projects like this.