This game is not a stealth game, it's an action game with stealth elements.
This game was supposed to be a "simple" action game but they gave you more tools for stealth and went with it. Aged like milk as a stealth game.
For more information look here very interesting read.
https://www.reddit.com/r/HiTMAN/comments/adfnk2/the_making_of_hitman_codename_47_discover_how_io/