LS said it well in his verbal lesson
Silver 5 4 3 2 1, Gold 5 4 3 2 1 Promotion series
these are all constructs created by Riot to give you a sense of accomplishment.
So in reality, if you are " Gold 5 " depending on your winrate / numbers of games played ( ties into MMR ) you might still be just another " Silver " player. These labels shouldn't mean much, but they're still a decent indicator for what MMR level you are in. But can be misleading, because a Diamond 5 player can have Plat 2 MMR and a Gold 2 player can also have Gold 5 MMR.
In my opinion Gold 5 is nothing too major and being stuck in Silver after playing over 500 games last season to get to Gold 5 is not surprising at all to me.
I don't think you're guaranteed to beat or solo carry Silver players just cause you were Gold last season.
As for roaming as mid / side lanes feeding.
Low elo really is about solo carry potential. Either that or you play jungle to take off the enemies jungle pressure and keep your lanes afloat.
Naturally the players who are better will be able to inch themselves slowly towards a big snowball victory. But people make the excuse about being in low elo and how it's a very bad practice environment.. When in fact, they are probably making huge mistakes already in their respective MMR, so yes.. low MMR is punishing you for something and you obviously aren't correcting these mistakes.
Regardless, I think anyone who makes an excuse about an inability to improve because they're stuck in " elo hell " is bull shit. Climbing isn't heavily weighted on how well your team does, climbing overall depends on your individual performance, especially in lower MMR because it's so easy to crush players who are absolutely clueless about how to handle a player who's capable of getting themselves miles ahead of the enemy team.