Ah but that's the beauty of GraphQL, a query can actually fetch data from several systems: the db, the cache, the search engine, etc. It's all abstracted away.

But let's say you have a timeout, and they have a retry, then suddenly, your server is now spammed by all the clients retry again and again a query that worked a week ago, but today is too heavy because of a tiny change nobody noticed.

And even if it's not the case, you can now break the client at any time because they decide to use a feature you gave them, but that you actually can't deal with right now.