Its also only protects one person AND requires concentration. Its very hard to look at a concentration spells as "top tier" just because it denies you access to so many other spells.
And it lasts until that concentration ends. If you use it for one round and then dump concentration to cast another spell the next round then it is comparable to barbs. If you use it for 2 or more it is clearly more powerful (and that assumes you don't have something else you want to cast).
What I meant with this spell is that since find familiar is normally cast on a previous day (and is a ritual), its not really competing on spell slots with other spells. So I don't really see it as an "either/or"....I would happily have both!
You do not need to cast it as a ritual. Sure that is a benefit, but it can be cast using a slot as well. It can't be cast in combat, but it can be cast every time you take a short rest.
It is not an either or, but it is more powerful than silvery barbs.
You are also assuming shield is automatic. Yes a +5 to AC is a big boost, but it in no way guarantees the wizard won't be hit. And absorb elements, sure it takes out half the damage....but you still have to make a concentration check. Meanwhile guess what helps with that concentration check....silvery barbs. You can apply the boost to yourself afterall, so if the enemy does force you to make a save, you can reroll it if you need to. And if you don't....well you have a whole minute to apply it to another concentration save should you need it.
If your DM rolls publicly it almost always results in a miss, more importantly it works for a turn even when it "fails" to stop the attack you use it on.
If you compare this to Barbs, the "no effect" will happen FAR more often on barbs AND barbs does not last a turn.
On Barbs, if the DM rolls privately and the players have no idea of the enemies target, the Barbs spell will change the effect of the targeted roll less than 50% of the time. If you know the targets save or you know what roll he succeeded with, you can slant the odds to your favor, but if you are playing hidden rolls with no idea of stats, Barbs will fail to change the outcome more than it changes the outcome.
At the end of the day, offense trumps defense. If a wizard is focusing their spell slots on defense and healing instead of controlling and killing...they are just going to be less effective. The best healed damage is the damage you never take. The best defense is the monster never attacking in the first place.
That is not true. Your wizard probably dies in round 1 against a White Dragon if he uses Barbs on his first turn. If he plays "offensively" and doesn't use Barbs and keeps absorb elements in his back pocket, he probably lasts 4 turns if he can stay out of melee. That is 4 offensive spells he could cast in the fight instead of 1 with a reroll.