Isn’t KiCAD limited to PCB design, or is my understanding out of date?

Cadence tooling is for end-to-end electronics design - from transistor/standard cell up to PCB.

So technically they’re both EDA tools, but one is in another league as far as sophistication goes.

People have hacked kicad into doing layout with the e.g. skywater 130 PDK. I wouldn't recommend it, but it's possible.

There's a whole lot more to an EDA tool than just layout or running spice though.