[rohit33]

This would rather vary with one's level of expertise. I remember when I was a beginner, I had to rely on the IDE that helped me get onto the speed. Sure there were tons of resources online, but a nick of continuity with the project may go a long way IMO.

[borplk]

Another point to consider is that even if you are a genius expert a lot, if not the majority of the code that people deal with has business specific models that you interact with.

It doesn't matter how well you know library X or the stdlib.

Some made up examples:

userRepository.findUsersWithPlan(planName);

customer.sendPaymentLateEmail(...);

Having powerful IDE assistance reduces the barrier between your thought and the computer.

When I think "send email to customer" I just want the shortest path to achieving that. I don't want to fiddle around or context switch.

Another advantage is that it can guide you into picking the correct option.

I have been burnt many times when looking things manually because you may find one option but not be aware that other options exist.

It's nice for the IDE to communicate to the human "now here's a list of valid things you can choose from".