Is ERA the only thing you are looking at there in 1984? Because if not, you would note that literally every single supporting statistic has seen a big year over year increase in Dylan's favor.
His FIP has dropped almost in half from 6.36 to 3.45! That FIP is actually a half of a run BELOW his current ERA. His WHIP is down 0.2, his K rate almost doubled, his walk rate has fallen by about 40%, and his HR/9 is down by half.
The hype is REAL.