Almost any layer can commoditize all around itself, as long as it has the critical mass of users. Google first got them with the search layer (who knew that was going to be such a thing in the late 90s?), which commoditized content. Netscape got it and then lost it.
Once you achieve dominance around a standard and necessary protocol at one layer of the stack, which is the whole game in tech, you can lay waste to competition in all directions, to ensure that no other layer of the stack commoditizes you.
What does, "embedded deeper in the value chain than your product" mean in layman's terms? Does it mean something which causally precedes the product?
We used to think that.
Apple has been very successful in reversing that again on mobile, so software is once again the complement.
"$1 for an app. Ripoff!!!"
For example, if you sell toasters, you better hope that electricity has been commoditized in the value chain that you operate in.
Another corollary is that you should commoditize ‘deeper’ complements when you need to defend existing money-makers when they’re at risk of bottom-up disruption. Mobile could have seriously hurt Google’s ad business, so it was a smart defensive play to commoditize mobile os on their terms via Android. To see what happens otherwise, note that they pay Apple $12B annually to have google as safari’s search default.
What I'm getting from this is: 1) in the causal chain of competitor's profits 2) better camouflaged from the POV of your customers.