Saying poe doesn't have prebuffing is not correct in practical terms. Sure, it happens at the beginning of the fight and not before, it's semantically not pre-anything.
But as long as design is concerned, you have little reason not to shift queue eldritch aim, bulwark, armor and other spells right off the bat. Their instant cast time means they'll all be up immediately anyway.
I guess the short duration was there to give some incentive not to, but then again we get back to the original, actual problem of poe (2 especially) = high level encounters don't require nearly as much planning as that. Maybe potd does, but I believe because of the nature of the systems, it's another sort of preparation (actual prebuffing through food and preparing quick use items).
But in the end poe's buffs are instant and combat-only because sawyer thought it was necessary to try something different from ie games, where you can just cast everything at every fight mindlessly. Problem is, it's necessary but not sufficient, and encounters (tuning of some monsters even) didn't support it as well.
In the end, poe's buffs problem doesn't come -at all- from prebuffing or not, hardcounters or not (game actually has these). Figuring it shows why one if better than the other is nonsensical, when the issue doesn't lie there to begin with.
EDIT : At the end of the day, the problem is that IE (I mean, d&d really, because that's what we're really talking about) way of dealing with it is that, well to take the example of the basilisk. Casting protection from petrification is a solution, and it feels good to see it work. But any other basilisk met will trigger this automatic good answer. Poe2 tried something interesting with its counter mechanic, as it's more real-time dependant (because short durations etc). There are some exceptions, like immunities through items and shit, but that's the idea. Problem doesn't change : is it supported by the encounters ? No, you can click the monster and it will go down.