it is impossible for us to do a side job that will affect our physical condition or even affect our main job.
The aim and purpose of working on the side is to help increase income without any effects, and it is true that in Crypto it can really help, we don't need to spend a lot of time and it can be done anywhere without affecting physical health and certainly won't interfere with the main job.
Not all side hustles affect the real job, but it all depends on how the person handles both jobs and decides for themselves if they will allow the job they took as a side hustle to affect their real job. There are people who are employees of a job that they are only working five hours per day, and they could still get an extra job as a side hustle, which they can work for an extra four hours before they close for that day. Some hustles could also be an online job that doesn't really take their full attention off of their real job. In terms of crypto, like you said, some people too are trading after they are off from work. Although they might still lose on the trades, they'll always get some profits too.