All of the issues that currently prevent FTL come from assuming that there is no universal reference frame, which all emerges from Einstein's theory of relativity. So far, observations seems to bear out relativity, but doesn't necessarily mean it's the final form for cosmology. Newtonian physics can also explain just about everything we observe in the universe, bar a few edge cases that prompted Einstein to think about relativity in the first place. Now we're starting to observe edge cases where the current standard model falls down, largely to do with the motion of distant objects and the rotational velocity curve of galaxies (how fast objects orbit in a galaxy vs how far they are from the centre - it doesn't tail off fast enough), to which the current answer is "dark matter"; a mathematical invention to explain the inexplicable. These particular edge cases are only edge cases because of assumptions drawn from relativity regarding things like the speed of gravity and the relationship between matter and energy.
Right now, a halo of some sort of dark matter is orbiting around Joe Biden's head and that's why he sounds like a mush-mouthed idiot. He actually speaks clearly, but his voice is muffled and his eyesight is restricted by the undetectable, unobservable haze of dark matter obstructing his face. It's also why he looks like he's melting. The extra gravity is trying to tear him down and is probably caused by a dense cloud of invisible republicans.