I never understand this point personally. If you're delivering value to the multiple companies you work for such that they like you, or at least don't fire you, then I don't see anything immoral in that. It's merely corporations who insist on people working for one and only one company at a time when in reality it shouldn't matter.
Completely agree. Do we insist that corporations only sell to a single customer? No that would be absurd. But insisting a person can only sell their labor to a single customer is seen as perfectly normal.
there is a chance you are going to have access to valuable information of competing companies, that would put you in position of power over them, and is a clear conflict of interests.
So it's like a lawyer serving opposing parties in court, nobody's asking why it's impossible
That's only true in that particular hypothetical. There are a lot of possible circumstances without such a clear conflict of interest.
Also, in the lawyer example, someone's freedom or livelihood is on the line. In the company example, it's a company's profits, which has a much less clear relationship to either of those two things, especially in today's world of 250:1 salary ratios.
