What is an RPG without sense of progression for your character?
What is an adventure game without sense of achievement in being able to do a task that you could not do before.
An open world would be a really bland world, if there was no occasion that you felt triumphant because you could reach a place that you could not reach before.
If all the monsters in the world were scaled to your level, and all the loot that you found were suitable for your current level, then why even try to explore, why even try to develop your character, why even try to play an RPG game.
If you do not want to sense the progression of your character, then you better play an FPS game, and beware current FPS games are moving toward RPG games with some RPG elements like skill development, different character classes and so on...