Leaderboard and raffles are great, I usually at least try to take 1 ticket, but as long as it's not so much wager amounts as whales are tough to beat;)
In my opinion, raffles are great because you can join and win raffles but with leaderboard, you will need big capital and so many playing times. It requires you to have good playing strategy to make sure you are in top leaderboard list but still be able to balance your net capital from your bets.
If you are careless, you will put your capital at risk by playing too much and let your emotion controls your minds and actions.
Leaderboard is for whales and very professional gamblers. It is not for newbie gamblers and anyone with small capital. It is especially true about leaderboard on big casinos.
Some raffles, yes, like I mentioned, if it's tied to wager amounts (the more you wager, the higher you go on leaderboard and the more raffles tickets you have) then it's about capital and playing time.
But if it's tied to certain types of achievements, for example. How many BJs you get, or multiplier wins, or even like rate of profit/loss, then everyone has equal chance (except those with not a lot of time, but autobetting also helps here!).