I'm now hosting my web app over VM in Google Compute Engine, and thus I learned that GCP also provides a DNS service called Cloud DNS. However, it seems that this service lets you add a DNS record on your domain, which is exactly what you can do in a popular domain seller's (e.g. namecheap) console.
I also think that most domain sellers also provide the interface to add records to the domain. So I wonder whether people have any chance to use Google's Cloud DNS on a domain purchased in another domain seller, which I assume is the standard in current web hosting.
Note that Google hasn't selling domains until recently, which makes me confused further.
What is the point of using Cloud DNS and what kind of advantages does it have over just configurating it on the domain seller's website? I use namecheap for your information.