The way I'm hearing it here, folk just weren't using potions if they weren't a bonus action? Even out of combat? My players always use potions as prep for a fight, or to recover from one. They go through a lot of potions
I even use potion miscibility tables! They don't each drink multiple buff potions (typically) but they still use a lot.
Different experiences for different tables, I guess.
Maybe it's just my experience, but I think something shifted over the past 25 years or so. I remember back in 2e and 3e it was common to do a lot of prep work before facing major challenges. If you were going up against a red dragon, trying to get any sort of fire resistance you could, cold damage, dragonslaying arrows, etc. etc. was part for the course, with groups planning out adventures like Shadowrunners.
But then I started to see a lot of DM advice about countering such strategies- Disjunction traps, antimagic, obscuring the information players could get, tricking them into making all that prep worthless. Suddenly the time honored practice of "scouting ahead" was actively discouraged, as monsters with special senses became the norm, and especially in the 3e era, you started to see skill points dumped into Listen and Spot on enemies (because why not?), to the point that in order to stealth, one needed to be invisible (to both normal sight and darkvision), flying, intangible, and protected from divinations or scrying.
Players who used magical divinations found those actively discouraged as well, with top tier play in 3.5 being called "scry and die" where players would attempt to teleport straight to the major foe, fully buffed, skipping past all other content.
4e didn't even bother making those tactics available for the most part, forcing players to engage with encounters. There wasn't really any reason to avoid encounters, as characters were designed to be able to handle many fights consecutively, and most of their resources were encounter-based or at-will.
By the time 5e rolled around, players often don't know much about the situation they're facing so buffing before combat has simply fallen out of favor. Taking an action in combat to buff as opposed to actively attempting to defeat challenges is rarely worth the effort when most fights end in four rounds. Why drink a potion to give yourself 25 Strength (a mere +2 to hit and damage) for 6 attacks when you could just make 8 attacks? Even if you have a potion of fire resistance when facing the red dragon, the monster does quite a lot of non-fire damage with it's melee attacks and the healing paradigm is such that downing a healing potion with an action is a desperation move, as enemies can generally deal far more damage to you than even a supreme potions 10d4+20 is going to (a CR 10 Young Red Dragon, for example, deals 46 damage on average with it's multiattack vs. the supreme potions average of 45 points of healing)!
Even though I still seed consumables in treasure with an eye for upcoming challenges, by the time the party faces whatever encounter I've prepared them for, said items are generally forgotten about in a bag of holding somewhere (or worse, sold for cash!).
The impact of buffs are weaker, the good potions are expensive and time consuming to make (and that assumes the DM allows for a magic item economy in their game- many don't!), and concentration basically destroys the impact of scrolls used for this purpose. The days of layering buffs on the Fighter before combat are basically gone. You might get a Haste or a Fly and a Death Ward (with the consumable budget going towards a daily Heroes' Feast!) but it's more likely that Haste or Fly is going to be a Hypnotic Pattern or Evard's Black Tentacles.
TLDR: players aren't used to having the option to prepare due to a lack of either information or access to resources. Characters are built to not really need to prepare for most encounters. Using actions in combat that don't directly contribute to victory is seen as "losing slower" as opposed to "winning faster".
Even with bonus action potions, I can tell you that they still don't get used a lot more in my games, because 5e designers decided almost every character needs to be using their bonus action for other things on their turn. Even if someone were downing basic healing potions every turn, it amounts to a lousy 7 temps a turn. Compare that to the 1d6+level temps a Twilight Cleric hands out with no cost to other players' action economy!*
*You can argue that the TC is overpowered, but it's still something 5e designers created, supposedly playtested, and published with the idea that this is perfectly acceptable for the game.
