What is flawed is not that there is an implicit grouping on all queries. It's that the implicit grouping changes, depending on a set of rules that consider stuff written in several places that are not explicitly related to it.

You are asking if it makes sense to have an implicit grouping at all; it very obviously absolutely does. And grouping by individual row is the very obvious default. But I do totally support adding that keyword expressing the default. All defaults should be expressible.