Your understanding is about 8 years out of date.

The Nexus line followed the JDM model you describe, ending with the 2015 Nexus 6P designed by Huawei. Starting with the Pixel in 2016, Google has been the designer and seller of record for all their phones, accelerating with the acquisition of HTC's phone team in 2017. The 2021 Pixel 6, moreover, used Google's in-house SoC ("Tensor"), which had been under development for years, rather than a Qualcomm chipset. That was a significant milestone.