You must have barely explored and avoided Shrine quests.
The fact you decided to finish the game after just 55 hours contradicts your claim you looked everywhere, because some of us are still discovering locations after 100+ hours.
Why rush? Savour this game, people.
There's a game playing philosophy I ascribe to when playing amazing open world games where I purposefully don't scour the map on my first playthrough but rather go with my gut instincts when making my way to the end. This way, I have plenty of content left to discover on repeat playthroughs in the future. I just hate forcing myself to exhaust content, although I have to say it's been difficult to do in BotW just because of how varied and compelling the world is.
I finished the game at ~150 hours but I know there is plenty left in the world undiscovered for multiple future playthroughs.
I think the beauty of this game is that you can finish the game in 30 hours and still have had a legitimately great time.