Lets say you have a trace that's 4mm wide that skips across a slot in the ground-plane. Is this good or bad?
1. Why is it 4mm? Is this a high-current line / power line of some kind? A crude power-plane that's just oversized for a trace? Is this a switching regulator with a bit of switching noise? Or is it a "quiet" power line, like a battery or LDO-line?
2. Is this trace actually ground? And the 4mm is to "jump" across the gnd-slot to provide a controlled return-path for some other line? What is the relationship of this trace vs another trace?
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If its a fat line on a switching power supply with a ton of current, maybe its a bad idea. If its a fat gnd, maybe its a good idea. Its all contextual. Its not very clear how a hypothetical ML tool would figure out this context, outside of like learning to read data-sheets and/or the EE writing down the purpose (very precisely) on each net... which probably is slower than just routing the trace manually to begin with.
Eventually.
Or hell, that PinC1 is an input vs output.
Modern chips have very flexible pins. Many microprocessors (and MCUs) can configure any pin to be input, output, tri-state output, pull-up output, or pull-down output, for example, with different properties in each state. Some pins can be analog (on-board op-amps), others can be digital and high frequency, still others can be digital but rarely-changing / effectively DC for the lifetime of the application.
Each scenario changes how you'd route a trace.
On a long-enough timeline, ML tools will become a natural fit for placement and routing. It is a rather dumb thing for humans to have to deal with, at the end of the day, but the existing tools are just not good enough to take over the job. At least not the tools that most of us have access to.