Tier 1 and 2 they are totally ok, even with the not very damage oriented build he does.
On reddit someone already tried a bit harder with relatable math behind it.
Tier 3 and 4 removing concentration at level 13 might have done the trick for single target damage. Especially when the capstone and level 11 abilities only buff this spell.
With removed concentration on level 13, the single target damage would be exactly on par woth other classes.
If you look at area damage though, ranger brings way more to the table than a rogue...
And this is not something treantmonk looks at in those videos, what he explicitely states more than once.