As others have stated, editing symbols inline needs to come back in some regard. I do appreciate the ability to have symbols added to a centralized page/artboard which helps create an on going and overarching symbol pattern library, and love that it is harder to destroy designs with accidental symbol editing, but I am not a big fan of being required to jump into a dedicated symbols page (akin to smart objects) as it adds unnecessary complexity and time to many aspects of design that were previously quick and an advantage over other tools.
Perhaps by holding a hotkey to allow inline changes, coupled with a verification modal or something of that nature would be the right blend of the two solutions. The modal could say something to the tune of “update instance”, “update instances on artboard only” or “update all symbol instances” which could prove very useful (to me anyway), particularly when rapidly designing various layout options and treatments. Requiring the dedicated artboard/page can slow the progress pretty significantly.