Thing is there is some history behind.
I would assume devs changed the ranked system in a way to get more players into the game by making a big change for the ranked for S17.
S17 everyone complained that the Ranked climb was too easy and pretty much everyone who wanted achieved Masters (second highest rank in the game). Streamer Pro Sweet did it without using guns and doing zero dmg in something like two days. So probably the devs felt a bit humiliated about this. And based on complaints & comments they changed the system so that its the opposite of easy climb.
So for S18 they made it harder by making it more difficult to climb but they kept certain things in the game (placement points matter more than kills) which allowed exploits in form of zone healing to rank up all the way to the pred. And even hold the pred rank by just staying in the zone for the entirety of the game.
For the current S19 devs added promotrials to the game to make those people exploiting having to really play the game.
Devs are really trying to improve the game but with competitive F2P PvP there will always be people looking to exploit & cheat -> ruin it for others.
If you have the passion, keep grinding bro. During climb try different legend classes. It helped me reset the MMR and allowed me to get more suitable lobbies.