Platinum 4 is forever rank...

@dioangelIt's hard but it's definitely possible. I've been able to solo Q to diamond in season 8, 9, and 11. In this case the simplest way I can put is like this.

this will happen often but if you have scenarios where you often get hardstuck gold/plat duos, hard stuck plat 4's, randoms who pretty much only play rank as their "pubs", and people who have decent gun skills but make some of the most dumbest decisions. The goal here is to try and take the leader role. often times, if you have good stats with your legends such high kills, a 4k/20 bomb, triple triple, or a diamond badge from a previous season to name a few, they'll probably be willing to play off you since it shows your competent and capable, It's not 100% needed but it definitely helps alot. If you do get to lead, go for smart fights, good positioning, and mobility/movement legends that can get you in and out easily if needed. You can definitely do it with non movement legends if your comfortable enough but it's going to be a bit harder. 

If they're the type that can't keep up, choose to do their own thing, too scared to fight with an advantage, or male awful decisions, them play with them till things really go south and then just play your life and rat. The ratting part when you get bad randoms or people who make bad choices sucks but it can allow you to just either lose little or gain a little more.

If you get plat 3's to plat 1's than those are the games you need to take advantage of. Most of these players tend to know what they're doing, are less likely to be bad or throw games, and/or are former diamond and masters/preds. Try to play off of them or try communicating with them as much as you can if possible. 

Rank is tough with how unpredictable plat lobbies are but it's certainly possible.