Comment by owenversteeg

It is absolutely true for industry.

It's not just IoT. Look around you in your daily life. Your average person has a few super-dense complex PCBs around them (laptop, phone, maybe a TV etc) but they have at the absolute minimum a few hundred simple PCBs. Your average household doodad these days requires multiple PCBs (power, control, and communications are typically separate.) How many things do you own with LEDs in them (including your lightbulbs?) How many modern cables do you own - because they all have PCBs in them now! I recently tore down a popular non-smart home appliance that's basically a fan, and it has five PCBs - one power, one control, one for the buttons on the top, one for the buttons on the side, and one for a sensor, none of those were off-the-shelf, and this is not unusual. If you really want to lose your mind, look at cars or children's toys, you'll go insane. Your average American with a car and an apartment, or a modest selection of modern children's toys, will own well into the four figures of simple PCBs. I think it's quite rare for your average person to own more than a handful of phones and laptops.

Beyond consumer products, still the overwhelming majority of PCBs are very simple. You say "all the weird hyper-specific industrial electronics" yet go into a sheet metal shop or a train factory or a refinery and count the ratio of simple PCBs to complex. Every sensor, every lightbulb, every cable, every scanner, every connected device... look at how simple process control is for most processes, or how simple most PCBs in most motorized devices are. The employees' smartphones will be the majority of the complex PCBs on the floor.

Now that I think of it - I don't think it's possible to buy or use a complex PCB without multiple accompanying simple PCBs. They virtually never take 110v, they typically take 110v->USB-C->5v DC, so that's two simple PCBs for power conversion plus two USB-C PCBs. You might use the device with a display (countless simple PCBs, its own power etc) or a mouse (yet more...) or some earbuds.