To install a degoogled Android aka custom ROM is way more efficient than to degoogle native Android aka Stock ROM.
However there are several ways to at least reduce the amount of spyware on Stock ROM:
seek out all apps, you don't use, and uninstall or deactivate them
if you can do neither or in addition follow the method described by XDA developers (as stated in the article as well not all apps can be uninstalled without risk - so be careful)
You can install LineageOS GSI (generic system image). GSI, as the name implies, is generic; it means that the OS won't know your actual model, so it'll have some little weird things, like the camera location in the UI.