You cannot expect that the development of technology brings only positive effects without negative effects, that is impossible. Like, why don't you think that without robots replacing humans there would be more workplace accidents? In addition, if you have ever operated and managed a factory, you will know how serious the damage will be if one day a worker suddenly quits his job and does not notify you in advance. That is also considered one of the disadvantages of using humans as labor while robots do not.
Everything in this world should have positive and negative side. It is true that we can't expect the technology brings no negative impact. Not only about robots, even smartphone brings some negative impacts for human. So, it is something we can't avoid, we only has an option to deal with the negative impacts.
Well, when we must quit the jobs, we must have other jobs to do. The robots may reduce the number of workers on the company. But the positive side is that people will be motivated to think more innovative to have alternative jobs.
I am also aware that, as technology develops, many people will be unemployed, but why don't we upgrade ourselves and adapt, instead of forcing the whole world to stop because of our backwardness? If you are afraid of losing your job or becoming unemployed, always actively improve your knowledge, qualifications, skills...to avoid being eliminated.
If the existence of robots will replace some jobs, people must move to other jobs. However, I think the robots won't totally replace the human jobs, it just reduce the number of the employees. And some jobs seem irreplaceable, it only can be done by human. So, I think we don't need to much worried about the future of available jobs for human.
Agree, if we don't want to be unemployed, we must have good knowledge. We also must have some skills that can be useful for varied jobs.