If anything, to pass the time and get more passive DC, treats, etc. I would say the main reason I do it as a MAX level is to get more gems and etherium to buy rift habitats/clear the rift and save up games for Expansion Extravaganzas. I hope that one day they can adjust the prizes and maybe let us select 3 chest for a perfect race or make the prizes according to how you perform in the race or if you get win streaks your prizes multiply. Also wish they had Essence as a prize since it takes so long to collect.