As a reformed physicist, I know all too well that the speed of light in vacuum © is widely acknowledged to be the fastest than any message can travel - and therefore the fastest ANYTHING can travel. (True, light travels faster in some materials than in vacuum, but we have the argument that the speed a message travels depends on group velocity not phase velocity, and group velocity is always equal to or less than c.)
The theory of special relativity, where all this comes from, starts rather than ends with the assertion that c is the fastest anyting can travel.
Special relativity works (so far as we can tell) - its predictions are borne out in experimental results, mainly (for those experiments at any where near c) with sub-atomic particles.
But for hundreds of years we were all perfectly content with Newtonian mechnanics, which basically placed no restriction on maximum speed. Einstein produced a fundamental update to Newton’s theories that said there was an upper limit.
Sooner or later, there is going to be a major update to Einsteinian mechanics, which may or may not remove the restriction on faster-than-light travel. We may have to wait a couple of hundred years though…
Call it wishful thinking if you like, I have always intuitively felt that the restriction is too sweeping to be unbreachable. We’re not about to start swooshing around the galaxy like Captain Kirk anytime soon, but the unverse is an inconceivably large place and it would be odd if some beings somewhere were not several steps beyond Einstein in working out how to achieve faster-than-light travel.