My read on some of the current melancholy is that the millenial generation is starting to hit their mid-life crisis. Seeing the inherent meaninglessness and inanity of much of corporate work is part and parcel of that. AI makes the contrast more stark, but not new.
Or to come at it another way: the system we live in - capitalism - is defined by the process of 'creative destruction' (coined by the economist Schumpeter). We are always iterating on technology, making it better, finding new optimizations. When these are found, very often one class of people is put out of work while another class of people gains employment.
Whether this process is desirable, moral, ethical, etc. is not answered by the observation, simply that this is how the system works.