High HP and armor is good for people...if they're tanks. The issue lies with ZoS implementing many forms of damage mitigation and HP boosts to basically anything. Skills that shouldn't grant armor or mitigation do so. The ease of attaining damage reduction and stacking HP is, and has been, ruining the PvP experience for years.
Cyrodiil is a combat zone between the three alliance superpowers. Lore aside, people MUST die. I myself have a DPS in PvP that has more HP, resistances, and regen than my healer while simultaneously being able to dish out enough power to take people down. How and when did it get to this point? People need to be forced to make decisions in the stats they want. The CP system throws this whole process out the window by providing free sources of HP, armor, and regen. When people don't need to worry about defensive gear or where they get their regen from, they have the privilege of stacking all the damage sets they want with zero repercussions to their defensive capabilities.
I would like to point out that there are also too many heal-boosting sources. We have Major/Minor Mending and Vitality. We also have Healing Received and Done. We ALSO have +% healing bonuses on sets. That is just plain absurd. These buffs are manageable only if they require an action to activate them like Major Mending from a Resto Staff, but not from a Warden for merely healing anything with a Green Balance ability under 40%. Major Protection for slotting Flare? Really? Minor Protection on both bars for slotting Dark Cloak? Really?
There is something we have incessantly asked for for years now and at this point it clearly shows that we are simply being shrugged off: capped cross-healing. This is quite possibly the most important change that we need in Cyrodiil. A limit on the amount of HoTs on people. There are features in the game that can be used to effectively implement this cap: Battle-Spirit and group sizes. Everyone with Battle-Spirit shall be limited to ONE HoT of each kind IF, and only IF, they are in a large group. This shall include healing from non-group members as well. People in large groups shall also receive diminishing returns in healing done/recieved, whatever, per group member. Obviously this won't end Ballgroups or Zergs, but it will limit their power when going against small hordes of solo players or groups. Most importantly, it will not harm or decentivise small-scale grouping or PvE. Ballgroups are already powerful in the sense that they are more coordinated than solo hordes, and it is nearly imposssible for solos to stop them. Not because they're "good" but because they have the advantage of the absurd healing mechanics.
Notice how damage has nothing to do with any of the things I just mentioned. Every single issue with PvP balance derives from poorly planned healing mechanics. Fix the healing problem. If people don't want to die in PvP then they should not be in PvP.