Stock investing has upward bias due to productivity. Also inflation offset. You can check long term S&P growth since inception. Stock market has positive EV on average. It's a positive sum game.

Sports betting or gambling has nevative EV and you lose more (on average) than you win.

So they are like night and day.

Even if the diffrence is 49.9% odds versus 51.01% odds that is worlds apart when it comes to laws of large numbers.