Parent comment specifically mentioned H1B visas as the problem. It doesn't have much to do with how good you are. You can't just choose any other job. You need to find an employer who has a H1B visa Program support. While I'm sure that there are employers who offer this support and still have some quotas available, the choice is very limited in comparison with the whole line of work you are referring to, plus in this case the leverage that the employee has is very little so many will choose to stay and endure but not as a preference but just to avoid the problems.
You're confusing "forced" to mean legal slavery and "forced" to mean that the worker would have to make very significant and unpleasant changes to their life that a reasonable person would say that they shouldn't. Nobody is trying to imply slavery.
There's a whole host of behaviors that are legally unacceptable in the workplace because telling people to just get another job isn't really a solution.
No one is claiming Musk is forcing these people to work at Twitter. The claim is some people are forced by the visa system to choose between (a) working at a place they do not like and would not endorse, (b) leaving the country, or (c) taking a huge risk that they might have to do (b) anyway.
The point is not to say that Twitter or Musk are benefitting from forced labor. The point is to say that we shouldn't think everyone working at Twitter is is endorsing Twitter's decisions or enjoying the workplace as is.
