Digital randomness vs physical randomness for one. Code can be subtly weighted easily in the direction and degree you want without regulation or oversight. Your roulette wheel’s loss of randomness is random itself and tampering is easy to see for regulators who absolutely exist and are inspecting. Even digital slot machines are heavily regulated. Your trust isn’t in the casino, it’s in the state it occurs in. And like yeah something fishy might be happening in a casino in your state. But nobody has stricter statisticians than the Nevada government. Their state’s economy relies on it.
Also physical gambling sells an experience outside the home in a specific atmosphere. Online gambling feels like the equivalent of getting a vodka faucet ran into your house next to the water. Sure you can indulge responsibly in that situation, but it’s not made for that purpose and it’s going to be much easier to find you’ve slipped into a serious addiction that’s harder to avoid.