Survivability is a huge thing in abyss and high level domains.
Shields basically increase your DPS output by immeasurable amounts. Diona in Abyss 12 is basically better than using a Pyro character - honestly (at least if you have a well equipped damage dealer).
It's the same with Xingqiu's E/Q ability.
Depending on what team you run, you actually need his interrupt resistance which also directly translates into survivability unless you like being pushed around and exploding every 0,5s while standing in Bennetts ult when you fight CinCin Mages, effectively dealing 0 dmg to them.
Not to mention that some things literally one shot a very well equipped DPS character.
Especially characters like Klee who have low base health amounts.
If Zhongli would be a pyro character, everyone would run him as sub-dps btw.
If he were Ice/Water, everyone would run him as aura support.
They need to buff Geo, unless a geo-character is strictly overpowered, you might as well just run Ning.
Shields should work like the new guitar-girl shield.
They should deal element damage (of the type of the shield) to surrounding enemies.
That way Geo-characters would be great aura-support and it would actually be useful to use elemental mastery (at least it wouldn't be useless) if it buffs that damage.