It is not meaningless. The "advanced" classed in AD&D have specific role playing restrictions that 3e does not have because of the change in design philosophy.
AD&D Paladin
-Can't own more than 10 magical items
-Can't retain wealth
-Must tithe 10% of income
-Doesn't attract followers
-Must employ only lawful good hirelings
-Must always be lawful good
3e Paladin
-Must be lawful good.
That's a huge difference in character descriptions and is absolutely not interchangable as you mention in the slightest.
It is, though.
Must tithe income? Can't retain wealth? Ok, that's great. You can't buy magic items. What else are you going to spend the gold on? Not much of a limitation. Same with the amgic items - when your magic items are literally "What the DM gives you," only having ten (Which is a huge number) isn't much of a limitation.
THAC0 in AD&D caps at 1 and AC caps at -10. The best warrior in the world will always have a 50% chance to hit the most defensible opponent. A level 9 character can match the fighting capability of a level 20 character provided the former has magic items, high strength, and weapon specialization (a +2 weapon, +2 from strength, and +1 from specialization, all of which are easily feasible at 9th level, brings a 9th level fighter to the capabilities of a 14th level fighter without magical equipment/bonuses).
Spell casting is the only thing that improves dramatically with level beyond the HD cap with priests achieving 7th level spells at 14th level.
So not only do you flat out admit that non-casters literally do not upgrade, but that spellcasting is the most important thing and the only thing that dramatically upgrades. This is an important thing to mention!
A level 9 character in 3e can never match a level 20 character short of ridiculous optimization and the level 20 character being unoptimized. Because BAB drops rapidly with iterative attacks, a +5 can be the difference between your second or third attack hitting on the money or missing horribly.
To what comparisons? A level 9 and a level 20 wizard in 2e are just as unmatchable. The only thing you've proven so far is "Yeah non-casters are even worst in 2e then they are otherwise."
Saving throws in AD&D don't work like that; they're linear and class dependent. No matter how powerful the enemy is, the target's level determines the difficulty of the save. The difference between a level 15 fighter and level 20 fighter in AD&D is
Save vs. Paralyzation: +5%
Save vs. Rod: +5%
Save vs. Petrification: +5%
Save vs. Breath: 0%
Save vs. Spell: +5%
I know how 2e saves works.
What you've just proven is, again, that the 2e fighter has
higher save increases then the 3e one does due to the static nature. You're arguing my point for me.
A level 20 fighter in 3e has 15% better fortitude saves, 5% better reflex, and 5% better will. Saving throws can be increased faster than the spell DCs making saves in 3e more valuable than in 2e where they show diminishing returns at 9th to 11th level depending on the class.
Uh, no. The percentages you use there don't work. Have you played 3e?
You have to hold something up as comparison. The save increases a fighter gets are miniscule compared to the 2e one because saves aren't a static number. The fighter's saves other then fortitude go up dramatically slower then a wizard's DCs do.
For the reference, a 10th level druid's THAC0 goes from 16 to 14 (+10% to fighting capability), his saves improve by 1 (5%), and he receives 2 hit points. An 11th level druid, the highest a druid can be before having to compete for 12th level, he receives +2hp and 1 5th level spell.
Wow. Absolutely massive.
See the bold?
You
just admitted that spellcasting is the only thing that dramatically increases. You
just admitted that spellcasting is by and large the most important and most powerful thing in 2e.
So yes, you're correct. That fifth level spell
is absolutely massive.
A 3e druid going from 9th to 10th has 1-8 hit points, +1 BAB (+5% to his attacks), +5% to fort and will saves, wild shape 4x a day, and 2 5th level spells because 3e clerics/druids gain magic at a faster rate. An 11th level druid can transform into tiny creatures, his BAB improves again, and he receives 6th level spells.
Comparison. Do you make them?
Monsters in 3e likewise improve dramatically harder then 2e does. The actual curve of powers (theoretically) remains the same - PCs got stronger and harder to kill, but so too did monsters. The 3e dragon and 2e dragon aren't even comparable; the 3e dragon is stronger in every single way. A level 1 orc in 2e and a level 1 orc in 3e are equally dramatically different.
What breaks druids is, you guessed it, spell casting (and wild shape). Not "how good they level."