Well i think one thing we should understand is that there are people with the means and influence to manipulate anything and these will go to great lengths to exercise that advantage over others. So im not saying most online gambling games are rigged but they can be
A good casino doesnt have to fix anything unfairly, this type of business is highly profitable just with a steady stream of customers. Thats the main argument against corruption, they would not choose to shoot themselves in the foot.
Generally the safest places then are also popular, well established with a line of regular customers. There will be review sites also I think.
Ask a mathematics student about fixed games but short answer is no, the odds stated are for real The house wins by general usage