Every American should also understand how this all works with classified documents before jumping to conclusions as well. As stated previously, there are a ton of government documents that are "classified" that have no business being considered classified, but the government does love its secrets so that label gets slapped on as many things as possible.
Secondly, it's not like Trump or Biden was sifting through a filing cabinet with a pen light in their mouths picking through the juiciest, most highly classified document to slip into a briefcase and sneak out. It was more likely that during transition a bunch of aids box a bunch of papers up, some of which ended up being classified docs, and that's how they ended up in Trump and Biden's hands. Neither one of them probably even know the contents of these "classified" documents.
People need to understand the laws surrounding government records, retention, and classification. Easily very highly probable that every single administration and congressional rep is guilty of this at one point or another.