I can provide you with an overview of the perspectives on the beauty of quantum field theory (QFT) compared to other approaches such as string theory or loop quantum gravity.
Quantum field theory is a framework that describes the behavior of particles and their interactions using fields and quantum mechanics. It has been tremendously successful in explaining and predicting the behavior of elementary particles and their interactions in the framework of the Standard Model of particle physics. QFT beautifully combines the principles of quantum mechanics and special relativity and has been extensively tested and validated through experimental observations.
Many physicists find the beauty of QFT in its mathematical elegance and its ability to unify different aspects of fundamental physics. It provides a comprehensive framework for understanding the behavior of elementary particles and their interactions, making it a cornerstone of modern theoretical physics.
On the other hand, string theory and loop quantum gravity are attempts to go beyond the Standard Model and incorporate gravity into the framework of quantum mechanics. String theory postulates that elementary particles are not point-like but are instead tiny vibrating strings, while loop quantum gravity proposes a discretization of spacetime at the Planck scale.
These approaches have their own aesthetic appeal and mathematical beauty. String theory, for example, has the potential to unify all fundamental forces, including gravity, into a single framework. It also provides a consistent theory of quantum gravity and has interesting connections to various areas of mathematics.
Loop quantum gravity, on the other hand, offers a background-independent approach to quantizing gravity and provides a discrete description of spacetime. It has made significant progress in addressing the issue of singularities that arise in classical general relativity.
Overall, different physicists have different opinions about the beauty and appeal of each approach. Beauty, in the context of theoretical physics, often refers to the elegance of mathematical formalism, explanatory power, and the potential for unification. Ultimately, the choice between these frameworks may depend on their ability to make testable predictions and provide a coherent description of our universe, which is an ongoing subject of research and exploration in the field of theoretical physics.