why my teammates are so bad now

Getting matched with more dead weights on console too, yesterday had 2 teammates die cause they didn't know what heat shields do, they just mad dashed with non mobiles, and 1 didn't even have heals on him.

The only solution to your problem of getting bad teammates is to use voice comms and find people to play with. Even if you can just find one other person to duo queue ranked games or even pubs whatever you prefer.. Having 1 other person on voice comms will often help keep your third with you and keep them in the fight. Call out everything you do that is relevant to your teammates whether it be to push a fight or play it slow and hold back. Ask your teammates what they need whether it be batteries, a weapon attachment, ammo.. etc. Make sure to also let them know if you need something. Most of the time if you ask polietly that you need a certain item you will usually recieve it. Sometimes people are greedy and or just don't care but most of the time I have found if I just ask I will get the item from them if I am nice about it. Honestly the best thing to help random teammates is just to communicate non stop. When you are rotating to a new location make sure you mark it and say things like "this area is good because it has cover and is on high ground". I am sure you already know these things that I just mentioned but unless you already have people to 3 stack with, there is no other choice. 

i guess i have to boost whole server to get out my rank

I can agree to this.  Seems like I'm getting nothing but trash every single day now. 

Why are the devs changing core systems of this game after years of sucess?   Matching seems to be horrible now, the new ranked system is really horrible. 

Dev's.  You're changing the best parts of Apex that kept this game alive all these years.  Are you sure you want to be changing core game mechanics like this?   I am a day 1 player, and an everyday player, and in my opinion you are making bad decisions here.