I run through, categorised, and compiled each class kit, which includes active skills, passives, class sets and sripts into spreadsheet.
Categories include: Burst, Sustain, Survivability, Healing, Pressure, Group Utility.

I didnt consider a quality of abilities, only its quantity. For example - Warden have 27% of its skills categorized as pressure, and only 6% is burst. But wait a minute, Warden is a brust oriented class, isnt he? Indeed. Thats because those graphs represent only quantity of skills not its quality. 6% of burst, which are represented in a single skill - shalks, are more than enough to build an effective burst build around them. But when you look at the arcanist, it has 8% of burst, but thats doesnt make them a good burst class, because dread and tides king gaze are not enough to build a strong burst around them.

Looking through each skill, I categorised them based on theirs main function. You may argue that puncturing sweep have a heling, which makes it a good survivability tool, and you will be right to some degree, the thing is, first and foremost its a damage dealing spammable, and then a healing tool, so it falls under a pressure category with auxulary function.

With that out of the way lets look at what we got:

Overall Classes composition: Overall, representation of different aspects spreads pretty much evenly. We see that every class has decent amount of pressure skills, wich is confirmed by popularity of pressure builds for PvP, with DK's being on top.
Plar, Sorc, NB, Cros and DK have a wide virieties of options for burst damage.
Wardens, Cros, Arcs and Templars have a decent kit for healing.
NB and Necros have a decent amount of options for sustain, as well as a bunch of sustain passives.
Wardens, Cros, DKs and Sorc have a decent kit of survivability oriented spells, which includes mitigation bonuses as well as mobility or powerful self healing.
Arcs and Wardens have a bunch of group support spells, that include buffs, debuffs, stuns, immobilises, repositioning tools, restoring resourses for allies, etc.

Once again, quintity doenst correlate with quality.
Something like templars Luminous Shards would definetly outpace Nature's Gift in resourse return, its all about the amount of different options.

And now to the main part. All of this doesnt matter anymore, since you can recompose your class with different skill trees, your character composition will look quite differently from what you are starting with.

In this new era, a better class will be able to keep the desierable aspects of the class he plays, and reinforce it with subclassing.
At the utmost, you wont be able to change class scripts, class sets, and 1 class line of your own chooise.

Now lets look through each class, and analyse how its aspects spread over its skill lines:

Dragonknight: Dragonknight have a nice orginised skill lines. Most of DK's pressure is in the Aedent Flame skill line, Draconic power burst is isolated, and works with pretty much eveything, you can use it with any burst skill and will be effective in the variety of combos (ex. Deep Fissure -> Deep Breath -> Take Flight, Deep Breath -> Take Flight -> Assassins will, etc), as well as Earthern Heart capability to boost any combo with undodgable/unblockable CC plus full pen + hight defense corrosive, all of DK's skill lines decent on its own, as well as in conjuction with each other.
Only thing that I would like to see its Talons swaped with chain. Overall composition of skill lines wont change, but chains are signature of DK's tanks, and will fit nice in tanking line, while burning talons are great pressure tool that DK's will want to keep with them, if they decide to go full damage.

Sorcerer: Sorcs are in the bad spot. Overall composition of sorc is nice and balaced, but each individual line is incomplete without other sorc lines. Storm Calling cant burst on its own it has only burst support with increased LA damage, dealyed execute and hard CC, Daedric Summoning, while housing most of sorcs passive survivability, has no Major resolve or tank utility like pulls of taunts, Dark Magic have no resourse return for allies or strong debuffs (brittle, vulnerability, cowardice, etc). Every line have a bit of group healing, which isnt the case with any other class, that have their heals consolidated to one line. In order to not become a dead class, sorcs desperatly need at least one of its aspects consolidated to one line, and for the love of divines, its shouldnt be pets. At least, move Daedric Curse into dark magic, to have a direct burst in one line and burst support in the other.

Templar: Templar is interesting, since it have unique way of building burst. Purifiyng light requires damage to feed it, Jesus beem requires target to be at low health to become effective, and this damage comes from Aedric Spear pressure. Mark target with light, pressure it with jabs and sweeps, once the puryfing pops burn your enemy with almighty beam. While restoring light is just great for healing and survivability on its own. Aedric Spear on its own is decent pressure tool, and can support a bunch of diffferent burst combos with its passives, pressure, and blockpiercing stuns. Dawns Wrath, in theory, should also be fine with different combos, if only ZoS hadnt nerfed beam that hard. Now its just a dead weight that plars are eager to shake off, and swap for assassination or whatever else.
Either unnerf the beam, or buff dark flare to be a decent burst ability, to breath some life back in ours shining skill tree.

Nightblade:
Warden:
Necromancer:
Arcanist:
NBs are good. Its skill lines are all specialised to do its thing, which makes them easy to swap, and easy to appropriate for other classes.
Warden, Arcs, And Necros are all post morrowind classes, that have each tree directed at doing its own thing.
Only problem with Arcs and Necros is figuring out its class unique resourse with isolated lines. Bone Tyrant and Solider of Apochrypha have a poor resourse gen to be used on their own. Its even worse with necros since the nerf to summons count that concerns amount of corpses active.

Balncewise we have a great road ahead, of tweaking and changing numbers, costs, buffs and debuffs.
But composition concerns class identity and overall combat design, and in order to preserve less fortunate sorceres that lose a big chunk of its identity no matter what line you swap, ZoS have to at least consolidade some of its current aspects into one line, or clean it up as a whole making each line dedicated to its own thing.