For your first point, I agree that pl does fall off in mid game. On the other hand, even if spec is way more active now, would you still agree that she is weak early, capable mid game, and strong late?

For your second point, what do you mean exactly by lines not existing in dota? I get that you are much stronger after completing bkb as opposed to before even of the difference is 50 gold. However, the power spike in question can still be displayed and portrayed by lines so I am having trouble understanding your lines argument.

Wouldnt spec or pl be a power line as they are weak early, capable at mid game, and strong late?