I think GP was exactly right when he said AI is amazing at micro, but that humans could win using macro pressure. Open AI 5 is an incredible achievement, but for Dota players it hasn't solved Dota. The best analogy is probably something like playing a fixed strategy in Poker, but never varying it; your opponents will eventually figure what your strategy is and ways to exploit it.

What you mentioned with having a courier for each hero is actually a well-known tactic called "bottle-crow" and was popular in Filipino Dota from 2010-2015. Each support hero would buy a dedicated crow for each lane and a bottle. Then the cores would ferry the bottle to themselves constantly from base, but this tactic got nerfed to death with the change "crow flies at half speed with an empty bottle". You are right that OG didn't deal well with this constant source of health regeneration, but it was largely limited to the laning phase. After the laning phase ends, humans can use their superior macro (i.e. understanding of map movement) which is a definite weakness of the AI.

Against the simple AI that comes built-in to Dota 2, you can be behind by a ton and exploit splitpushing against the AI, because doing any structural damage against buildings will force the AI (who are gathered up for a push) back, and you will win if you drag the game sufficiently into the lategame. There are indications that similar tactics can be used against the OpenAI 5, which is bad countering invisible items/heroes and playing against splitpush [1]. Deciding whether or not to continue to push and which heroes to send back to defend is one of the hardest strategic decisions to make in the game, even for humans. The finals of one of the TIs, NaVi vs. Alliance, was lost on getting such a decision wrong. Eliminating some key splitpush heroes minimized the probability that OpenAI 5 would have been forced into having to make such a decision.

OpenAI 5 would have lost against OG if any of the following had been satisfied:

- had the entire heropool been available (certain natural splitpushing heroes like Furion, Tinker, Phantom Lancer, etc.)

- had the series gone long enough for them to uncover AI's weaknesses (which were apparent to the viewers and later teams). OG's captain even explicitly said "Give us 5 games and we will figure it out."

- had the prizepool been big enough for OG to take the game seriously enough to warrant picking a splitpushing strategy which is considered "cowardly" in some circles.

[1] https://www.reddit.com/r/DotA2/comments/beyilz/openai_live_u...