There are multiple ways to earn bitcoin! Actually everytime you would receive fiat money you could also get it in bitcoin. There is/was a service around where you could get your monthly payment from your job paid out as bitcoin or just a percentage of it if you want to (not sure if it still exists), or you could sell online services for bitcoin.
Then the obvious ones:
- Faucets
- Gambling
- PTC
As you can see, the options of getting bitcoin are limitless.
All the options that you have listed are bullshit and a waste of time and money and a person who have good experience in the world of bitcoins will never waste his time an money in the above sites as faucets will give you payment in peanuts and with higher transaction fees it won't give you anything in return and most of the PTC sites are scam who will disappear with your money in long term and I don't need to say anything about gambling as you are smart enough.
beside that a lot of other ways are there through which we can earn bitcoin but i think still the best way is to trading altcoin, in fact there are a lot of altcoin which have still good potential to increase therefore they can give you a good profit , but for becoming a good trading you need experience and for getting experience you need to spend a good time in trading without investing a big amount of money.