Winrate affecting climbing speed

Ok so, I have two accounts. One that was Platinum I last season, now it's platinum IV with a negative winrate (about 60wins and 85losses (42%)) The second account, is a new smurf I made, I got 9/10 games from placements, got gold I and went all the way up to platinum V 56 LP atm with a positive winrate (about 45wins and 32losses (59%)). The problem here, is that even though the mmr is around the same on both accounts. And even though I'm convinced I can climb back to platinum I again on both of them. it would take me a lot more games on the new account compared to the one with the negative winrate. Now I get that the game tries to keep your winrate around 55%, and that you'll probably get butchered in match making once you go past that and even more if you're around 70%. So unless you're smurfing, you WILL lose games to keep your winrate balanced. But that also hinders the ability of a same player to climb to a certain elo, on two different account, even though they're both at around the same division. This problem has bothered me for quite a while, and some of my friends too. Even youtubers like phylol for example suffered from this, getting many unfavorable games in a row on an account, and not on the other. I'm not saying I'm playing perfect, and yes, if I was a better player I could've carried more. But there is no denying that there is a SIGNIFICANT difficulty of climbing between the two accounts.

What are your opinions on this matter guys? and please share if some of you guys had this issue, for the sake of confirming.