Do caster out of combat options matter?

[Telok]

In your case, it would matter greatly if no one had access to certain spells. But the point is, that's not "the game". That's you, and your particular world building and your approach to the matter and what you want to add, include, etc.

It matters because you have decided it matters.

That raises an interesting question: Did I decide to make it matter that some classes have out of combat magic and others don't?

Because I wrote a relatively mainstream setting with flying castles, underwater civilizations, pocket dimensions, planes, and a limited number of links between them. Some of the world building and adventure potential that arose from that is predicated on things like there not being convenient planar portals, commercial teleport services, easily acessible flying critters to carry armored riders, or common herbs to allow people the breath underwater. I didn't do that to screw over noncasters or make having noncombat spells matter, I just didn't consider it because the game already gives the options to do all the stuff right in the PH.

So did I choose to make noncombat spells matter by not thinking about adding stuff inconsistent with my setting to enable a party of guy-at-the-gym characters to go everywhere and do everything? Or does the base default settings of the game make it matter by giving the standard and assumed fighter-mage-priest-thief party the noncombat abilities to do that stuff?

I think that the game is designed to give characters everything they need to go on all the adventures within the default PH rules. The game design makes the noncombat spells matter because they're the usual way to do stuff like access the planes and explore underwater dungeons. Adding handicap access for parties without noncombat spells is the optional extra stuff in the DMG that the GM can choose to use or not, as it fits their campaign and setting.

Aside: as time goes on I'm getting more interested in if the game can be played past lower-middle levels without the assumed tank & healer stuff, or how much bending and alteration to published campaigns has to be done to enable that sort of play.