AWS and GCP Conducts different certification for different roles playing.
Being the top Cloud services competitors globally, they have different prioritized technologies implemented for Cloud services. AWS is matured enough by occupying the cloud gamut as 1st service provider in implementing them, years together. Where as GCP is accelerating their services year on year on the technologies those are in demand. Similarly it has evolved with professional certifications also accordingly.
You can see the comparison video from the below link: