You are right, there are some traders that are making money from trading almost every week, although they do experience losses too but for the expert traders who applies a good risk management strategy, there win rate is usually higher than the losses they get and they still remains profitable in their trading journey.
Not only earning money weekly, some traders even can earn money daily.
If people do daytrading, they will take profits daily. However, we can't expect to earn huge profits in daily. I'm sure those people who do daytrading won't target to get profits very significantly.
The reason why I said weekly is because at least some traders who doesn't stress much with their trades will always trade just maybe twice or thrice in a week and they try to take positions that they have had enough conformation of making profits. That why I said weekly, some scalpers experienced lots of losses too.