I think it's still valuable since we have tons of waste in our orbit that has already proven to be problematic. Maybe it's not cost effective if you only consider the cost of sending a new satellite vs the costs of repairing an old one, but if you take into account the reduced waste and the problems you avoid by having a cleaner orbit it may be worth the extra money.

No, you learn about servicing things in space. If we are to ever send humans far from earth (mars perhaps) they need to have the ability to service their craft should something break. If a satellite breaks in space sending a new one is probably the most cost effective thing to do. However I have a moral problem with the idea that humans sent to mars would be told to die if something goes wrong. That means the ability to repair the things that go wrong.