Disagree. The TNG computer was used via voice input when it was efficient to do so, which is exactly how it should be. There were plenty of computer consoles, laptops, and tricorders/phone-like devices that were also used, especially with certain types of tasks. The crew could technically fly the ship and fire weapons via voice commands, but that only happened occasionally, in situations where it made sense. Also, when Picard wants to record himself playing a musical instrument, saying “Computer, begin recording” is simply convenient. It serves no purpose to the story or explaining anything to the audience. It’s just a tool. One that I would very much like to have.

The best example I can think of in favor of what you are saying, where the computer does kind of serve the story and helps the audience, is the episode where Doctor Crusher gets stuck in the warp bubble and she has a lot of conversations with the computer about what is happening. But even then, she is out of her element, needs a lot of help from the computer, and it seems more convenient to do so via voice than anything else. She still travels to different areas of the ship to carry out actions, even though she probably doesn’t have to in case. The computer is clearly at its best for simple actions and answering questions, even if it can do more. The characters understand that and use the technology accordingly.