So you are saying that 100% every spell in the wizard arsenal is available by level up and there isn't a single spell that is only learnable through scrolls except for Shovel?
There's a few in Act 3 that is only learnable through scrolls (Artistry of War, Summon Deva and Dethrone), but otherwise yes. Wizards can only scribe what is in their spell list, which can be accessed via their level ups.
And if you already have access to EVERY spell in the wizard arsenal just from leveling up, what's the purpose of the scribing ability? Is it largely just useless "Flavor" for the class that isn't really an advantage beyond saving time at Withers when you want to change your spell loadout while still remaining a wizard or the spec you currently are?
Yes. It's largely a holdover from settings where Withers doesn't exist, such as tabletop. Whereby it is used to expand your known spells so you can have more options available to memorize for the day.
In BG3, with Withers enabling respeccing for free (Literally, if you pickpocket your 200g back since he doesn't care if you do or even if you fail...) enables you to freely swap out your known spells which obfuscates the need to bother scribing.
As such, the mechanic is mostly used by people doing single level Wizard dips and using Headband of Intellect to boost their Int to 17 to utilize certain powerful Wizard spells on their non-Wizard caster (As spell slots are shared so as long as you're a full caster you can scribe level 6 Wizard spells to use with your level 6 spell slots) - Which is not possible outside of BG3 because the actual ruling in TT is that your ability to scribe is based entirely on your Wizard level, not your spell slot level.
Don't get me wrong, have a druid with maxed Wisdom, Intellect and Charisma because Strength, Dexterity, and Constitution are completely worthless to me makes for a pretty good party face but the fact that those other stats are completely useless for 1 of the 3 subclasses seems off. The Spore actually care at least about Constitution and Dex and they aren't even the melee oriented subclass.
Dexterity and Constitution aren't completely worthless, you yourself even mention using Gloves of Dexterity meaning the stat has worth.
The thing about Druids is that they're primarily casters, with a secondary melee class mechanic. As such, using a Druid to its fullest, will involve using both spells and Wild Shapes (Aside from Spore where the idea is to use Symbiotic Entity in lieu of Wild Shapes). This is more pronounced outside of BG3 (Because BG3 makes resting basically free, you can always have your 2 Wild Shape uses available for basically every fight), as you have to economize your resources meaning you will be using spells a lot and saving Wild Shape uses for when it's most beneficial.
Ergo, you'd be wanting Dex and Con just the same as any other caster, in order to provide AC (In case you're not using heavy armour), initiative and health. Even if you're going Circle of the Moon which has more focus on Wild Shapes, without free resting you're limited in how often you're able to utilize Wild Shapes and thus must fall back on the spell casting available to the class and will therefore be in your humanoid form and hence your physical stats are relevant.
My big thing I am getting is, I can understand some of these things likely translate over very well to the table top, not so much to the videogame section of it.
Most of what is poorly translated is not to do with it being a video game, but rather in this specific video game's designs.
Wizard scribing is rendered moot because of Withers. Circle of the Moon feels bad because you're able to Wild Shape for every fight due to ease of resting allowing one to forget that they're a caster class (Thus you start to think "What's the point of having 3 stats do nothing because I'm Wild Shaped 99% of the time?").
