thank you for admitting to that which everyone here knows is true, but some choose to disingenuously, hypocrtically deny.
but how does this authenticity work? Is no UK reggae authentic?
there are different definitions, perspectives, and interpretations, as seen in the awesome Peel story, nothing is absolute.
so YT or Gentleman can be argued to be, in many ways, more authentic than some hypothetical Jamaican who is merely going through the motions and cynically churning out what he thinks will sell according to market analysis.
Is it a sliding scale from total authenticity to fakeness?
sliding, and more than one scale for sure, but again, no absolutes. the concept itself is relative - but it doesn't mean absolute relativism
And does the sliding scale of goodness lie exactly along this authenticity scale?
no not exactly, and there are exceptions, but more often than not, i think it does.