Could you or someone else elaborate on the different type of licenses and why a company interested in licensing might opt for one over another? I was surprised by the OPs comment that few companies actually license microarchitecture as I thought that's what Apple has been doing with ARM.
It is what Apple has been doing with ARM, but as he said there's only about 10 companies doing this, compared to the hundreds (thousands?) who take the core directly from ARM. Even big players like Qualcomm seem to be moving to just requesting tweaks to the Cortex cores.
It's much, much easier & cheaper to take the premade core rather than developing your own. But your own custom design gives you the ability to differentiate or really target a specific application. See Apple's designs.
In reality, most of their licenses are processor (core+interfaces) or POP (pre-optimized processor designs).
https://www.anandtech.com/show/7112/the-arm-diaries-part-1-h...