I don't see any difference. In Roulette, you choose Black or Red, Odd or Even... and in Dice, you choose above 50 or below 50, they are both 50-50 choices.
No, you are not looking into the actual fact here. At Stake, dice game has 1% house edge and roulette has 2.7% house edge. There are 37 numbers on Stake roulette including the 0. Where the chance of getting 0 or any other number is 2.7%. But the chance of rolling the 50.00 or any other specific number is only 0.01% on the dice game.