In the most basic sense, a carry is defined as a hero who has abilities that augment their right clicking prowess, and boy does invoker have those!
He his expert orbs give him a very high amount of bonus int which translates to bonus damage, he has alacrity, a very potent buff that boosts BOTH attack speed AND damage, forged spirits that lower armor, cold snap that stun locks with rapid attacks and ghost walk for picking off enemies clinkz-style!
The most common excuse is “oh he’s a spell caster hero, you should be slinging spells, not right clicking!” But here’s the thing: his spells don’t just vanish when you build right click items on him. You can still throw around deafening blasts; after all, what’s a Sven without Storm Bolt? Try playing Drow without gust! Possible mana issues are patched up with Orchid, which covers all the bases an int based right clicker can ask for! (durability non-withstanding)
I’m sure there are more counter arguments and nuances to them. Could I be enlightened of them?
Source: https://www.reddit.com/r/DotA2/comments/sno3ya/why_isnt_invoker_seen_as_a_capable_right_click/