i have a pixel phone, but google is not the good guy here. Like in this example, it basically bundles stuff in a way, so if you want for example the store, you have to take other stuff also and that other stuff has its own requirements.
Google used to be more permissive with OEM "customization" and the result was lots of Bad Product Differentiation. Phone OEMs suck at software.
Huawei has a phone OS not based on AOSP, but you can't easily get it in the US.
Making a coherent OS product that doesn't get horribly mutated by OEM licensees is not easy. Vide Windows bloatware.
Google flexing in this way, arguably for the benefit of the user, is nonetheless anticompetitive and the courts are reaming them for it.