It’s been pointed out too that if the bots basically just draft pick the best cards, not because they are building anything specific, it’s working even against the strategy to draft just the best cards which would never win you enough to even get close to repaying your outlay.
In my experience, the AI doesn't pick cards by power. Sometimes I get passed something like Aurelia halfway through the pack, which is pretty insane and would never happen against humans. I'd say drafting against the AI gives you a better chance for multiple rares and generally good cards.
As for the general value of drafts: If you don't need many cards (M19 doesn't have many relevant rares for the meta), it is obviously pointless. However, drafting something like Ravnica or Dominaria will always offer better value than packs, even with a mediocre winrate. I usually pay 5.000 gold for an average of 2 drafts and each of them gets me at least one pack. So worst case scenario: I trade half a wildcard for a free draft.
Also, drafting fills the Vault pretty fast. I know that the Vault is a bad payoff for the lost value, but it is a bonus. 18-20 drafts equal a Vault (that is, if you don't need the commons/uncommons – if you need them, even better), so going by my stated exchange rate, you get a free Vault for every 10th wildcard you sacrifice for drafting instead of buying packs. A free Vault in addition to the value of the 20 drafts you played.