It would be an easy setup to play and do ok (easy to deal good damage against enemies in close range, easy to heal with and have divine shield, freedom, hammer of justice etc).

Any magic debuff can be removed with cleanse so can counter CC/roots/slow very good.

16 out of 20 seconds of uptime on blessing of freedom would make it hard to slow the paladins.

Weaknesses:
No gap closer, if you fight players that kite you then you can probably not do anything and they can probably also "bully" you by attacking you from multiple angles and then when you chase someone he just run away and the others attack you.
Can use Repentance as a gap closer to stop them if you are within 20yd distance.

Running out of mana easily (not sure how big issue this is if you choose a spec and playstyle to conserve mana, with shamans for example I could farm mobs nonstop without ever drinking, I think in pve you might be able to do that against single target and if you are in heavy advantage pvp situations).

Very short range, 10yd range on Judgement and Hammer of Justice, 20yd on repentance.

Limited AoE (I think it is only Consecration and you both need to spec into it and use a big chunk of mana, and people can move out of it in pvp).

Repentance, Blessing of Freedom etc are dispellable (for buffs it might not be a big issue since you have a bunch of buffs on you so hard to quickly remove spells like freedom, especially on multiple characters).

Same movement speed as other players in pvp I think (8% from talents, others have 8% movement speed from enchant).

Considering the paladin in the videos didn't use IWT, stopped all characters when he needed to heal (hard to not do that, but could be worth to fix that to not be so immobile), used divine shield on every character (probably better to use on only one that is about to die) and other things like that, there is room for improvement and even so it seems to be very easy to be strong with it.

Compared to other groups like casters having to face enemy, dies quickly against melee damage, can be interrupted when casting spells, likely much easier to cc (if there is only 1 dispeller then just sheep/fear it and dispeller/healer is gone) etc. Other groups that could be strong could also be so vulnerable.
Paladins wouldn't have too much of those vulnerabilities with the high armor, all can heal/dispel/DS and just IWT and press instant attack to deal damage.