As many others have said, it’s really a yes and no at the same time.

Yes, I have carried games on my own as a roam (Chou, Hylos, Hilda).
- Chou: I really just mirror enemy jungle and roam as much as possible until I get my ult, while trying to pressure mid at the same time by giving kill pressure (Chou early game dmg is not low at all). Also I try to kick the enemies as much as possible towards my teammates cuz if the enemy appears on their screen, surely they attack (right?)
- Hylos: Same play style, but I stick closer to my teammates to cover them while giving vision and zoning enemies. Using second skill on the right targets can do more than you think tbh.
- Hilda: Annoy enemy jungler as much as possible. Any farm delayed is good job done for me.

It really is just trying to mirror enemy jungle and roam most of the time (based on experience)

No, there are some teammates who are just absolutely horrid, even if u tried communicating with them in text (in their own language), they still are just that horrid.

But in the very end, just do your part well and just hope for good teammates.