Getting into this thread super late, but I'm surprised in the direction it took. Handwringing over access to the Plane of Fire and pointing at video game design decisions are just... odd to me.

There is a layer of this discussion that is missing a chunk of the problem - that this is a game based on decision making, and everything is made up. Yes, if you need to travel planes for the story, you'll have access to that because it makes the story work. But there's a tradeoff there. It would be a very different story if Frodo was told to destroy the ring by throwing it into Mt. Doom, who said "I don't know the way" and the response from the elves was pointing to a nearby staircase and saying "go that way, second door on the right" and he could just skip over to their Doom portal and chuck it in.

Out of combat options matter for casters because it limits their combat options - they have to make decisions on how much utility vs how much combat effectiveness they can have access to at any given moment. If a group of player sit down to start a campaign, and one person decides to go all-in about riding horses and jousting their enemies to death, that's a decision that can be made. At the same moment, if the DM knows they're going to be trudging through muck and squeezing through caves for the campaign, they really should let that player know that the thing they want to do won't particularly work for the game they're playing - not because it's an "incorrect" decision, but that those decisions won't help in this specific circumstance. Not telling them would be setting them up to feel the exact opposite of optimized.

Out of combat or utility options matter just as much for noncasters as well. Sneaking through an old prison if you have a rogue who can stealth through and pick locks is a very different game than going through the same old prison with only fighters and clerics wearing heavy armor - there's not much sneaking with all that chain and plate and, since they can't pick locks, they have to loudly smash their way through those obstacles. They can still make their way through, but the world will just react to them differently because they're interacting with the world differently.

But ultimately, each game is made up. At each table, the DM is making a game that interacts with the characters. I'm currently running Princes of the Apocalypse for my PF2e group, and one player (even though they knew what they were getting into) decided they were going to make their wizard's schtick that necromancy was their all-in. Normally, that'd be a terrible idea - PotA is essentially "Avatar the Last Airbender, but they're all evil" as a campaign. However, I just ran with it - I was already worried about how same-y the encounters would be, so I just dramatically upped the amount of Undead. The tiny sidequest about the crazed necromancer the "Lord of Lance Rock" in the book got expanded into a crazed necromancer that was supplying the 4 elemental cults with undead shock troops. Everyone is happy, and the only one who knows the difference is that one player who insisted on reading every published adventure for fun.

There's a certain strategy that I ascribe to as a DM that I've heard called "Shoot your monks". In 5e, all monks get the Deflect missiles feature at level 3, and in most games I've played or consumed an actual play of, rarely comes up. The "Shoot your monks" philosophy means that, if you've got a monk of the appropriate level, you need to add NPCs occasionally to encounters for the express purpose of shooting those monks, giving them the chance to deflect the missiles, and feel awesome. If you've got someone who can speak to animals, you should include more animals for that PC to shine when they defuse a situation or gain some information. If you have player characters with scouting potential, like invisible familiars, arcane eyes or wild shapes, give them the chance to use those abilities - they don't need to be able to scout everything forever (that's why there are doors in a dungeon, after all), but being able to ambush a group that would be ambushing them if the party haven't scouted it out.