Are 3 and 4 different numbers? Yes. But they are still numbers, so we can line them up and say that 4 is bigger than 3 and if we're talking about money 4 is better and if we're talking about debt 3 is better. If your bank account goes from 3 digits to 4, that's better. But what if you're measuring something and it goes from 3 to D? Well sure, D is the 4th letter, so maybe we can say it is higher and depending on the perspective, better, but it is also different.
Better is different, but different is not always better.
What is better for you can be worse for someone else. Or for the same person, some parts are better, some parts are worse. This is what has been happening with WoW.
But let's not get into vague ideas like lobby vs. world. Instead, let's talk paladins.
A long while ago there was no such thing as Forbearance. This meant that a paladin could use divine shield right after blessing of protection. Back then there was no mass dispel, so beside a bug involving lag and shamans, divine shield could not be removed. And it lasted 12 seconds. Take note of that time: even with a GCD that is enough to use a hearthstone. It was pretty sweet.
On top of that, Divine Protection used to be a funny sort of spell. It was basically a bad version of divine shield. Priests had a spell like this as well, one of their heals. And of course paladins had a purify spell which was like cleanse but didn't remove magic. Anyway, Divine Protection made the paladins completely invincible just like Divine Shield, but didn't last as long, and made the paladin unable to attack. Of course they could still heal.
Now imagine, as a melee class, trying to fight someone who can heal himself, wears plate, and has three different ways to become entirely immune to physical damage. Not easy!
Over time their toughness has been nerfed. Heavily. Now the bubbles last less time and can be removed, along with triggering forbearance.
It's not all bad though. It may be better overall. Better, but different. Losing all that durability has gone along with some other changes.
Damage has gone up significantly. Paladin damage is no longer a joke. Oh sure, run your numbers and you might find it is too low (I have no clue where it is these days), but wherever it is, it's definitely higher than it was. Mana regeneration is higher. Control of damage is higher. Just plain hitting things hard is higher. If a paladin wants to DPS, they have some chance at it. This was not always the case. People wrote songs about it.
Despite the durability of a paladin, they were not popular tanks either. With almost no regeneration, since back then it mostly came from spirit and seal/judgement of wisdom, which was nowhere near adequate, especially since using seal of wisdom would mean a huge aggro loss. It didn't help that only warriors had tanking sets. Even in BC paladins were in an awkward spot in gear design, using up stats for intellect before mana generation was sorted out in LK (mostly). On top of mana problems, aggro wasn't so easy either. While righteous fury gave a major boost to holy damage aggro, it was a magic ability and could be removed. This was trouble for some bosses. Again, even in BC there was a boss that would spam dispel magic, which made him very tricky to tank, since righteous fury was expensive.
Despite the durability, a quirk of the spell scaling system meant that using a low rank of flash of light with good gear could result in incomparable efficiency. Even with the crap regen, paladin healers could go for a long time, thanks to getting a good bit of healing out of a very cheap spell. So maybe they were good healers. For one target. Spamming one ability for hours on end. While wearing a dress that was clearly not designed for them, so it was not even remotely flattering. Ugh. Terrible times. These days there is gear designed for it, so the priests don't whine so much. The spells are more interesting. Even I, a person who never quite enjoyed healing, can say that paladin healing has improved.
And yet, and yet...
It was fun to see a rogue kill himself punching my shield while feeding me reckoning charges so I could punch back twice as often. I'm not saying that the same punch was giving both, since obviously if you're blocking you aren't getting crit, so no reckoning, at least until they changed it.
A paladin soloed* a level 60 40-man raid boss. At level 60. Thanks to an old old version of reckoning. Balanced? Perhaps not. Awesome? Yes.
* I suppose you could argue it was a two-person operation, since the rogue did help.
This video is why I made a paladin, made her protection, and an engineer. This shit was the shit. For some perspective, those plans were not easy to get, coming from what was not a particularly hard raid, but it did require 40 people and had a low drop rate. My first shields were made by another engineer, who it turned out was about to drop it (my timing is incredible), because it wasn't good enough. Psh. Who needs stupid stats when they can make mind-control helms and cloaking devices? That running around he did in the place with the skeletons, that was Scholomance, back when it was level 60, and really not a place for someone to be soloing. Of course a mage did it(the entire place) because they wish they were as good as warlocks. Of whom I cannot find a video of one soloing it. I'm sure I saw it... Surely a warlock can do anything a mage can do, but better; that's the whole point of them!
Anyway, balance was a hazy concept back then. Things are better now. Better, but different, and different isn't always better.