As for me online gambling varies on their capabilities depending on how the game earns profitable winning.
Every game will have profitable winnings if they are lucky. If they are not lucky then they lose. As simple as that. Online or offline is irrelevant because that does not "vary" your luck in any manner.
However players always trusted the game host as well as the team players came along the gameplay situation.
True, but then fixed games cannot be discerned from non-fixed games. In most cases the games are played in such a way that audience will never understand the nature of fixing but the conspiracy theorists will always be there.
Thinking about fair games, it doesn't have the assurance at all times because the game online has its own plans and strategies to follow.
Thats a wrong assumption to make. Learn more about provably fair system of games before you say such things. Rest assured those sites which have been running from age old times are not fixed in anyway.
I think there are really scam sites but it's only a few but not all. There are sites which are transparent with transactions and you can check them legitimately. Also, friend referrals are a big help (especially if you trust this friend not to bring you to harm or be scammed). I guess you will know if youre being played when you start to question the methods and once you have noticed a pattern.