Zelda creator Shigeru Miyamoto always knew that Navi was the "biggest weakpoint of Ocarina of Time" and once said "I wanted to remove the entire system"

gamesradar.com:

The Legend of Zelda: Ocarina of Time is an all-time classic - an early masterpiece of 3D gaming whose influence can still be seen to this day, and unquestionably one of the best N64 games ever made. But people have been complaining about Link's fairy companion Navi and her annoying advice since the game's launch in 1998, and she arguably set the stage for decades worth of irritating tutorials and hints in video games. It turns out that even Shigeru Miyamoto himself always knew that Navi's role in the N64 classic was less than ideal.

"I think the way we give hints is still a little too unfriendly," Miyamoto admitted in an interview for a 1999 Japanese strategy guide, which has been translated by shmuplations. "Speaking plainly, I can now confess to you: I think the whole system with Navi giving you advice is the biggest weakpoint of Ocarina of Time. It's incredibly difficult to design a system that gives proper advice, advice that's tailored to the player's situation. To do it right, you'd have to spend the same amount of time as you would developing an entire game, and I was very worried we'd be digging ourselves into a hole, if we pursued perfection there…"

Miyamoto went on to say that "if you read Navi's text, she says the same things over and over. I know it makes it sound bad, but we purposely left her at a kind of 'stupid' level. I think if we'd tried to make Navi's hints more sophisticated, that 'stupidity' would have actually stood out even more. The truth is I wanted to remove the entire system, but that would have been even more unfriendly to players. You can think of Navi as being there for players who stop playing for a month or so, who then pick the game back up and want to remember what they were supposed to do. It's a brazen excuse, I know. (laughs)"

These days, Ocarina of Time is not considered a particularly difficult game, but when it was new players were still coming to terms with the very idea of solving puzzles and fighting monsters in a 3D