Reaching rank 5 isn’t really that hard at all if you’re an ok player because win streak exists, you can actually get to rank 5 with like a 45% winrate if you play enough. Rank 5 itself is a mix of weaker players playing meta decks and better players playing meme/experimental decks. Getting legend is significantly more difficult but it’s achievable if you know how to play your deck well enough. From 5 to legend with a 60% winrate (definitely achievable for a good player with a t1 deck) takes on average somewhere around 120 games. You don’t have any winstreaks to prop you up. It will take A LOT longer if you’re a 52-53% player.
My tip: Play tempo rogue, games are fast which speeds up the climb. Also it destroys almost everything except warrior. Watch some good streamers that play rogue (Rdu plays a lot of it) and learn from how they play. Best of luck!