I think the key words here is "in the long run", that is the most realistic explanation on how the house edge will beat us. Of course, when we are lucky we can also win, odds like x10 or x100 is possible in any kind of gambling games, but as we know, casinos doesn't rely on that, they rely on the system of the casino that always gives them the edge every time you spin.
You’re right, House edge is like a cancer that slowly eat your bankroll without even noticing it until you play longer since casino returns has a slight decreased for a 1:1 payout.
A proper mindset will help you deal with that kind of gambling. The reason why casinos are profitable is becasue of that house edge, so at least understanding that will help us minimize the risk because we will no longer pursue trying to bet big to win big, just do it for fun, bet what you can afford to lose and stop withou regret when you lose.
Sports betting is one of the game that doesn't have that "house edge".
Not true. Sportsbook has a house edge. Check sportsbook odds for an even game. You can’t see an even match that has both 2.0 odds on each side since casino applies house edge by lowering both odds below 2.0 despite the winning percentage is just 50/50.
Expected Value(EV) should be zero for a sportsbook doesn’t have a house edge yet most of the bet offered has a -EV which means house edge applies.
Maybe the explanation have sense, but my personal belief, if you evade the house edge, just bet on the odds with 2.0 +... and 50/50 winning percentage is not really certain as the odds provided or spread are just estimates. Unlike in a machine operated game where it's completely correct as they created the system.
sometimes odds in sports betting are overvalued or undervalued, so that's the big difference that does not exist in games like roulette.