in short not really,
a jungler is more of an enabler that can enable your team mates to do amazing if they are doing good. but if they are doing bad you cant really do to much. sure you could camp there lane but you would lose XP and farm from jungle/ganks and you would leech there XP that would be bad for both of you.

Late game if you are fed you might be in for a chance of helping carry, but not really on your own

Every Offtank falls off lategame. Carrys are what matters lategame. Protect your carry and you win.

I would say, as a good jungler you can greatly carry, when your lanes skills are close the enemy lane skills. The jungler is most of the time really just the icing on the cake.

Imo you can carry yourself up the best when you have a premade playing support and play carry yourself. Because as a good carry with a support,
that protects the carry well, you can just destroy most uncoordinated teams in Low Elo single handedly.

its a kinda self sacrifice, if ur laner are feeding gnak the hell out of them, this will result in u underlevling but ur laners being ahead and will probably lead u to victory!

ps. if ur playing a kinda support/tank jungler try going for more dmg and less support items
fx. i carried with amumu 19/1/21 at first i was building GP10 and aegis, but it turned out our ashe was a noob so i sold my GP10 and got rylays and ROA

Get Janna.
Carry as support.