I don't see how Brand support even works

Let me list you out some pointers here:

He has excellent pokes

This may seem great, somewhat like a Zilean 2.0 there. But overdoing it will just lead you to carelessness by getting caught by Thresh's hook when all you wanna do is set up that WQ combo. And most of the times, your pokes will eventually resulting in stealing some of your ADC's minions, giving your own lane partner an unnecessary gold disadvantage, and sometimes, your attacks would end up killing the lane opponents. From that part, I can see Brand as a "kill-bot" or "mid-reject", instead of an actual "support".

He has a stun

The 3 listed above can do better stuns than Brand does, since first, Brand has to land one of his abilities first, and second, he has to cast Q onto an unprotected affected target, implying there is nothing in front of the target to block the projectile, simply a minion. But after that, what else are you worth?

has a stun which is on-point on a simple point-&-click. And to accomodate that, he has heals & an armor aura shield to support his adc even more.

, similar to Taric, she can be a point-&-click type of stun support as well, or an instant-AoE if preferable, unlike Brand who takes 0.5 second to set up that W cast. Her trip to a stun-activate is way simpler than Brand by either repeatingly casting E on herself, or doing continuous pokes with her point-&-click Q.

is a tank support, even if it takes time to set up that stuns, he can effectively block most of the damage well with his shield to protect his adc. Brand is squishy, and landing that WQ isn't such an easy task. What's better, Braum can split his passive on multiple champions, making him an effective CC dealer besides his ult.

He has the easiet spellthief gold collection

Yeah, so do . Bombs that can be used with no counterplay and attack in a 600 freaking range, a support that can insta-cast W onto two lane opponents at once, and some guy who can repeatedly throw his crows at a distance, which can bounces back & forth, or repeatedly hit the same target if minions are rare.

If I see another obedient dog who goes Brand support because "Riot says so, its op", imma just dodge. You're not worth it.