When you said you'd have a ranged encounter with a melee ranger, but would never do anything similar to the wizard.
Well, the world is not limited to four scenarios.
Oh I see what you're saying! Yeah I can see how that sounds- I will occasionally use a ranged or flying encounter when I have a melee-only guy in a party. Just as I will occasionally use an enemy who has legendary resistance or something.
And yeah, I suppose that might "turn off" the melee character in a way I wouldn't turn off a spellcaster (by depriving them of magic entirely). Although.
There are ranged options a melee specialist can employ. While they may not be as good as swinging a sword (I have never ascribed to the "just switch to a bow and you're fine" rhetoric- I understand that building to use a bow with any degree of accuracy or effectiveness can be an issue for some characters- though it's certainly a lot easier in 5e, which doesn't require composite bows or precise shot, and doesn't require Dexterity to be your very best ability score in order to hit), they do exist.
I will admit that there is an analogy to "not being able to use a weapon" to "not being able to use a spellbook", though I don't think it's quite apt because the special abilities of a Fighter are never turned "off" simply because they don't have a weapon handy.
Not in the same way as a Wizard being turned into a commoner with more hit points, at least. Which is the fundamental difference, in my mind, at least. A Fighter without his sword is still a Fighter, if a hampered one. A Wizard who has had all his magic removed is...not really a Wizard.
I just don't like heavy handed solutions to balance issues. "Because antimagic" "because rust monsters" "because removal" "because blue counterspells"...ah, sorry, getting a bit removed from D&D there...aren't really answers to me.
I look at the Wizard's issues as a consequence of the game's long history of creating tons of very specific spells to deal with various situations, and not bothering to give those to "mundanes" (not a fan of that term either, but it's perhaps less loaded?) at the same time, "because that's what casters do".
Put another way, a 7th level Wizard can take raw materials (stone, maybe some wood) and create a 2 story tower inside of 10 minutes once per day. Now that's not terribly useful in all situations, but when it comes up, it's amazing. And it's not like the spell is called "create small fortification" either. It has other potential uses.
Tell a veteran soldier, a 7th level Fighter, to build fortifications out of thin air, and it's going to take hours or days. And probably ability checks, where all our Mason Wizard needs is tool proficiency
. This is, to me, the core issue.
I don't mind a Wizard doing cool things with magic- the limited amount of spell slots per day is usually
a limiting factor. I don't mind that spells like Fabricate exist. I mind that all of these "silver bullet" and "narrative answer" effects are limited to spells only. That only spellcasters get them because it would be "unrealistic" for characters who don't access spells, and that, by design, the only thing really stopping a spellcaster from acquiring said spells is for a DM to step in and say "that's not available".
And there are frequently situations where "spell slots per day" are not a limiting factor, which gives Wizard great narrative power. As a video I just watched pointed out, a Fabricate using Wizard could potentially jump start an industrial revolution or wow the world with the equivalent of a mass produced Gutenberg Bible or something. And that's just one single spell out of an ever-growing list.
Anyways, enough reiterating the same points. As to your response about there being more than the 4 possible results of Grod's hypothesis- what else is there?