Flamestrike
Legend
We're not really seeing the 6-8 encounters either and we're running PotA.
Thats your DMs fault.
PotA does have long periods of empty days and single encounter days (as you wander around the place) though, with several 'zoomed in' dungeon areas (the various elemental cult headquarters) with those areas featuring several encounters with little or no chance of rest.
You cant exactly assault the Temple of Elemental Fire, nova a few rooms, then fall back overnight to rest.
I found the problem with PotA was players were able to too easily metagame when an encounter was a random 'solo encounter' adventuring day, and then employ nova tactics.
I countered this by re-structuring the occasional 'random' encounter, breaking it up into several smaller linked encounters. For example a random encounter of Bandits would be re-structured to be 2-3 waves of Bandits. The first encounter is the PCs locating a small Bandit scouting party [medium difficulty encounter]... and then this encounter is immediately followed by a larger force of Bandits a few minutes after the 1st combat ends [a hard encounter].
After those two encounters are dealt with, one of the bandits drops a map to the nearby bandit camp and a ransom note indicating that the bandits have several children who they are ransoming off, that they intend to kill by midnight if the ransom isnt paid (a hook to lead the party to encounter 3).
Encounter 3 is the bandit lair, a [deadly] encounter with multiple bandits, some thugs, a bandit spellcaster [mage], and a tough bandit leader [gladiator].
If the players dumped all their long rest resources into encounter 1 (thinking it was the only encounter that day) they're in for a rude shock when encounter 2 happens (and its a more dangerous encounter than encounter 1), and then after that, they then have to overcome a 3rd encounter before long resting; and that final encounter is even more difficult than the first two.
You do this (or similar encounters) once or twice, and your players instinctively self regulate resource usage and avoid nova tactics and the 5 minute adventuring day.