I don’t think so but as we have to respect Proven theories, I explain it like this
The speed of light is considered the universe's maximum speed due to the laws of relativity, which show that as objects approach light speed, they require infinite energy to accelerate further. While quantum mechanics suggests "faster-than-light" effects, such as entanglement, these don’t enable usable faster-than-light communication or travel. Philosophically, light speed sets limits on our understanding, although some speculative theories propose ways to deny it.
The speed of light is the fastest for particles. This suggests light particles have the simplest structure.
However, the speed of gravity and the coulomb force have been measured at millions of times the speed of light. This suggests forces such as gravity and electric are not particles and can be entangled. The similarity of force equations suggests only one type of entanglement medium.
In modern science : NO !
More seriously, there are many definitions of velocity, including of the velocity of light. As early as 1913, for a wavepacket, Sommerfeld & Brillouin distinguished among others group and phase velocities, signal velocity, front and summit velocities, and energy and information transport velocities.
Among those, only the latter are theoretically forbiden by Special Relativity: neither energy nor information can be transported faster than c.
In an hypothetical perfect vacuum, all these definition are equivalent, and the velocity of light (then unambiguously defined) is always c.
In dispersive materials, and in the linear regime, it is well known that group velocity, which is mostly a mathematical construct, can take almost arbitrary values. Group velocities higher than 300 c have been observed experimentally, as well as group velocities close to 0 or negative.
Yet, the most intuitive definition of the velocity of a wavepacket is the signal velocity, which is directly related to the Galilean velocity of a particle. And in some highly nonlinear regimes, superluminal signal velocities can also be engineered.
An exemple is the superluminous Brillouin soliton, which has been measured in Brillouin fiber lasers with signal velocities up to 1,7 c.
See for instance :
Article Observation of dissipative superluminous solitons in a Brill...
So scientifically, no, c is but one definition of the velocity of light, and definitively not the greatest.
And philosophically — I suppose that this raises two distinct sets of questions :
- One about our use of certain words and definitions, such as "the velocity of light" (thus implicitely unique, whereas it admits several different definitions), which, when deliberate, denotes a scientific programme, in Lakatos' acception, and thus strongly limit the generality of any derived proposition ; and, when subconscious, is the root of many pseudo-paradox and fallacies.
- And one about the physical status of the observer in modern science (both relativity and quantum science) — since any observer intrinsically holds information, and thus cannot be associated to any superluminal frame.