Taken from 5e Rulebook ;
A spell scroll bears the words of a single spell, written as a mystical cipher. If the spell is on your class's spell list, you can read the scroll and cast its spell without providing any material components. Otherwise, the scroll is unintelligible.
So , Wizard's should not be able to read/cast/scribe spell scrolls if it's not on their spell list. So any Bard, Druid, Cleric, Sorcerer, Warlock, subclass etc. specific spells should not be learned. There are some common spells amongst these disciplines rest is class spesific. Healing word is for example, Cleric-Bard-Druid,Artificier, Divine Soul only. -> Healing Word.
This makes Wizard too powerful and cannot be done just to balance out healing in my opinion. A big BUG/Error in my opinion.