It serves well for generic purposes of tracking the activities of Hugh Fantasy Action Heroes *who are gross overgeneralizations as s rule), not a universal simulation of human ability.
That's a False Dichotomy. There is a world of space between gross overgeneralization and simulation of humanity. It's not as if the 3e skills are accurate to the real world simulations.
Of course it is juat flavor, there ia no mwchanical contentto "Arcane" or "Divine" magiv. And I just showed how a Wizard can get enough Cleric stuff, in the rules as written, to make the concept work.
There is literally no difference in flavor between...
Human Wizard/Necromancer - Arcane
Level 5
5th level wizard/necromancer abilities
Cantrips: Chill Touch, Mage Hand, Poison Spray, Light
1st: Ray of Sickness, False Life, Magic Missile
2nd: Mirror Image, Ray of Enfeeblement, Cloud of Daggers
3rd: Animate Dead, Fear
And...
Human Wizard/Necromancer - Divine
Level 5
5th level wizard/necromancer abilities
Cantrips: Chill Touch, Mage Hand, Poison Spray, Light
1st: Ray of Sickness, False Life, Magic Missile
2nd: Mirror Image, Ray of Enfeeblement, Cloud of Daggers
3rd: Animate Dead, Fear
Your miniscule amount of real divine magic through the Divine Initiate feat 1) doesn't create the feel of a divine necromancer, 2) doesn't create the feel of even a divine caster, 3) has nothing to do with being a necromancer.
So basically you forced a square peg into a round hole in order to create a failed divine necromancer concept since it fails to be actually divine(clerical).
That you would be forced to push that square peg into a round hole to make a divine necromancer automatically means 5e failed to provide you with the concept. Unlike 3e which gives me several different truly divine necromancers to pick from.
One one edition provides us with the divine necromancer concept, and it's not 5e.
At any rate, it is abundantly clear from tge context of the video that Perkins was comparing Class options available in the PHB very specifically, and it is true that the new 2024 PHB has more Class options, 48, than any prior PHB iteration.
That's a white room comparison, though. Concepts and options are not simply class and subclass/prestige class alone. Feats and skills are also a part of the character options. For example, Great Weapon Master and Sentinal aren't class options for an evoker wizard. Those are warrior(not fighter) class feats. War Caster is a caster class feat. Sure you could take Great Weapon Master as an evoker or War Caster as a champion fighter, but why would you? Feats are gated by what they do for certain classes and subclasses.