No, being a co-author of various articles published in top peer-reviewed conferences or journals is not a sufficient condition for "getting a PhD", mostly because coauthorship does not show independence. It might be considered a necessary condition in some institutions, which often confuses students in believing it is also a sufficient one.
Being the main author or single author of various such articles might be enough to be allowed to defend a PhD thesis at some institutions, but I suspect that a "defense" would still be required to insure that the author understands the content of their publication, that they have a central thesis in those publications, and understand what a proper research process consists in.
According to Wikipedia, those studying for a Doctor of Philosophy degree are required to
- produce original research that expands the boundaries of knowledge, normally in the form of a dissertation, and
- defend their work before a panel of other experts in the field.
Developing the first point, a Doctor of Philosophy (someone who "got a PhD" for short) should be able to do their own research independently from others, which implies 1) having a good knowledge of the state of the art in some area, 2) being able to define and choose "good" research hypothesis, 3) knowing how to setup and implement research experiments or work to validate or invalidate such hypothesis, 4) being able to communicate clearly their work to the research community. Merely contributing to such research is enough to earn co-authorship in publications, but does not indicate an ability to fulfill all those roles independently from others. As an example, co-authorship is sometimes given to students who are making a minor (but real) contribution to the article (e.g. implementing and describing in the article a piece of software used in the experiment), but played no active role in some other parts (e.g. choosing the hypothesis, defining the experimental protocol, etc.). Such a student completely deserves authorship (see the ACM Policy on Authorship for an example), and will learn a lot about performing and describing research, but did not prove their ability to perform all the tasks required from a researcher.
In some institutions, being the main author of a number (e.g. two at my institution) of articles in peer reviewed venues might be a necessary condition for being allowed to defend one's PhD (not for just "getting a PhD"), but this should not be confused with a sufficient condition (which many students do). Note that it would allow to "defend", but not grant the diploma automatically: the PhD candidate would still be required to 1) compile the research from their various publication into a single document, with a central research theme and hypothesis, and to 2) defend it orally in front of a jury in a way convincing them that they have the skills to make an independent and ethical researcher.
I hope it helps!