@ECMO3
Re: limited by spells prepared, this ignores the power and utility of rituals.
Comprehend languages, for example, might not absolutely slam-dunk resolve a "negotiate with gnolls" situation, but it will absolutely solve a huge amount of it for ten minutes' effort.
Further, you mention the "flexibility" (not meaning scare quotes, just using your term) of the Ranger class, adapting to a campaign
across several levels, rather than all at once. For a game where things like "negotiate with gnolls" becomes an important occurrence, even an Evoker Wizard can adapt to suit the campaign better just by picking better spells: they don't need to be Batman Wizard, they just need to exploit the fundamental flexibility of "being a full spellcaster" to acquire a couple useful non-combat spells per spell level, especially if any of those spells are also rituals and thus don't need slots.
E.g., say you start off intending to go Evoker, max specialized in pumping out the
phat deeps, only to learn that combats happen about once every three adventuring days and you mostly are doing survivalist stuff, exploration, investigations, and frequent (albeit not
every day) diplomatic talks. You took only damage cantrips (
firebolt, sword burst, and
frostbite, say) and combat-related spells at 1st level (
chromatic orb, grease, magic missile, shield, sleep, Tasha's hideous laughter.) By the time you reach 2nd level you realize
oh, this isn't that kind of campaign, you need utility options and combat options shouldn't be your focus. Your 2nd level spell choices are
comprehend languages and
find familiar, and you pick Divination instead of Evocation. These are extremely excellent utility spells for this kind of campaign (social/exploration/investigation-heavy) and also rituals, so you don't even have to sacrifice your damage capacity in order to benefit from them. At 3rd level, pick up
scorching ray and
borrowed knowledge (and swap out
sword burst and
frostbite for
light and
prestidigitation with your next two long rests), and at 4th level
mind spike and
enhance ability (or
invisibility if stealth is more valuable) while grabbing
mage hand as your fourth cantrip.
Purely through built-in spell gains and changing up your intended subclass (as you did in your example), this character that started out intending to be a blaster has become an excellent support-utility caster well-tailored to the specific campaign. THAT is the problem here. It's not that the Wizard is being presumed to have every single spell on their spell list. It's that they can have a
massive focus on combat at level 1 and then pivot to being excellent in social and investigatory situations, or vice-versa. It's not a magical "I can have every spell at all times!" It's that with Wizard Level + Int mod prepared spells--starting at 4/6 spells at level 1 and rising to 8/12 spells at level 4 (assuming you start with 16 Int and take +2 Int at level 4, which...why wouldn't you?) is huge and quite able to prepare for two or even three different distinct campaign foci.* Prepare everything but
comprehend languages, find familiar, grease, and
sleep, and you still have an excellent spell kit. You still have several excellent combat spells (
shield, scorching ray, chromatic orb), while having several excellent generalist pure-utility spells. If the DM is nice to you and lets you swap out some spells, you might try dropping
grease for
silvery barbs (and thus probably leave
Tasha's hideous laughter not-prepared), but frankly you don't really need to give up terribly many of the spells you have on hand.
Now. What can the (non-spellcasting) Fighter do that is even remotely equivalent to that? Switch from planning to be a Champion to planning to be a Battle Master?
*And because you have Arcane Recovery, you actually get ceiling(Wizard Level/2) levels' worth extra spell slots, albeit no higher than 5th level. So a 4th level Wizard has essentially eight spell slots (or nine, I guess, if you
really need two 1st-level spells more than one 2nd-level spell.) Once you get your second Divination feature, you get
even more effective slots, since casting a divination spell...
such as mind spike...allows you to recover a slot of up to 1 level lower than the one you just used.