AI sucks ass for every serious task. I've used it dozens of times to work on research projects, and consistently it gives me responses that sound good, but have holes, like citing works that don't exist, mis-applying arguments, etc.

these problems never appear if you ask it standard questions, e.g. simple exercise questions from the classes. it always solves those correctly, probably because they exist in the training data. but try to ask it anything where logical inference is non-trivial and it starts splicing facts together in ways that don't end up straight.

anyways, all being said, it's still great for routine tasks, and for informing you about basic knowledge in a new field. since basic knowledge is all written down in books somewhere, AI knows about it quite well. also, coworkers make mistakes, and lots of them. if i sum up all the steps of progress that coworkers make and that AI make while working on a new project, i'd say it's about on the same level. coworkers tend to think about new topics more seriously, but also they often just don't respond, give up, never call back etc. meanwhile AI tries to output something, even if it's wrong.

all that being said, there will still be a decline in knowledge worker jobs, but not so much because of AI being excellent at actively exploring new areas and kinda spreading out to take over jobs, but instead because like 99.999% of our jobs are kinda routine jobs anyways. people always tell themselves they're special, and they are. but at the same time it's mostly routine jobs. these are not mutually exclusive. and that's why a lot of jobs are still going to vanish.