My job for the past few years has been to write the software that runs casino slot machines and their back-end systems (the players' club software and more). Roulette, slot machines, etc. work like this. If there is a 10% chance of winning, and I give you 3 times your bet, I end up winning because you lose much more often than you win that the 3x prize will not be enough to cover your costs.
But there really isn't even a 10% chance, games with really big prizes are almost impossible to win (like slot machines). How does it work financially between online casinos and slot providers? Do casinos pay them a fixed monthly fee to offer their games? Or do providers receive a share? They are not random, depending on how the word is used. A slot machine is programmed to have a certain amount of return. For example, on the Las Vegas Strip, most slots give ~ 92% of what is put on them over time.
Local casinos are higher, about 95% payback. While the number may fluctuate, that is variance, rather than RNG. Get a job that pays $300 a week. After work, go to a slot machine.
Look at the slot machine, don't insert money. The same thing, live dealer blackjack also works for me sometimes. He won another 1.5k online blackjack today. Slot machines are good if you play the right ones.
He won up to 13,000 in total in 2 weeks on the slot machines. Keep an eye out for blackjack games that aren't with live dealers. They are the least reliable games. When playing at an online casino, especially slots or table games, be sure to read T&C and make sure you are not manipulated or deceived in any way.
Most casino games in any casino, both online and in real life (especially in the US). (US), are provided by the same top 3 or 4 providers, and they would have no reason to make their online versions more or less manipulated than the IRL versions.