Clickable objects are part of the scene.
They are not using a modern scene. They are using the 7.3.5 to load 1.12 scenes. There is no clickable objects for guild banks.
The UI for guild banks (summon guild bank perk) would still be in the client. Possibly the API too. Removing that would be in order, for bloat reasons, and just in case reasons.
Inventory managment was a thing in classic that no longer exists in the modern game with mount tabs, collections, and larger bags.
With Guild Banks you can potentially hold huge quantities of materials on a single character and that opens up massive potential for influencing classic AH markets. There are other economic considerations such as the trickle down to tailoring markets as demand for bags would potentially drop as a result.
Managing a legit guild bank using an alt/alts in Vanilla was something that took time, effort, and all importantly trust in the responsible person. Take away the time, effort and trust in the community for the sake of conveininence and you’re left with the current trash systems and lack of engagement pervasive in the game since (imo) LFD and the subsequent Cataclysm expansion.