Most games online require devices with high specifications and good internet connection to run it properly. While many gambling games can be run with low end devices. That's the reason why I prefer online gambling rather than games online. More over, most gambling games are simple.
Not totally, if you are a hardcore gamer you really need to have high specs on your pc but it depends on the genre of your game.
There are games that dont require that much, you can play them with a normal specs of a pc has.