Biden was never in a state of power to "de-classify" or posses classified documents. Neither was Pence... Pence apologized.
"Guilty of what"
Well, if DT is guilty for having documents that he actually held the power to declassify and posses.... and he is being incicted.... Why are Biden and Pence not indicted? They never had that power...
It's like watching two cars speed by you... followed by a police car, in chase, and the police officer is charged for speeding...while the two other cars are not...
You misunderstand the charges and why they were brought. Let's forget about any of the documents being classified, at the moment, to examine what occurred.
Trump, Biden, and Pence all ended up with records that were "Presidential documents" (or "records) from their time in office (the VP's documents are more or less considered to be "Presidential records" as they were part of the Administration). The Presidential Records Act (PRA) require all Presidential documents (or records, from both the President and the Vice President) to be turned over to the National Archive (NARA). For the moment, let us assume that none of them had any knowledge (since their offices, when they leave the White House, are typically packed by staffers), at least that can be proven, that they had the documents.
In the case of Pence and Biden, the evidence suggests that both turned over the documents that were found, as soon as they were found and identified as Presidential records. In Trump's case, NARA found that various records had not been turned over by Pres. Trump, and they asked former Pres. Trump to return them. While former Pres. Trump ultimately returned some papers, he did not turn over all the records NARA had asked for. After dealing with it for six months or so, where they felt they were being stonewalled, they followed the steps listed in the PRA for assistance in getting the documents returned -- they contacted the DoJ.
The DoJ contacted former Pres. Trump and were not able to get the documents turned over, so they went to court -- the court issued a subpoena requiring former Pres. Trump to turn over all the documents. At this point, Trump's attorneys said there were a few more documents that had been found and they were ready to turn them over -- and (based on statements former Pres. Trump allegedly made to them), the lawyers (under oath) claimed that all the Presidential records had been returned.
Shortly after this, the FBI had informants tell them that former Pres. Trump was still holding documents, that some of the documents were Classified, in various areas of Mar-A-Lago. At this point, based on the reports, the FBI went to court to get a search warrant to find any documents still being held by the former president. The FBI raid found quite a bit of material, including over 100 Classified documents.
If former Pres. Trump had turned over the documents when first requested by NARA, there would have been no charges. In fact, if former Pres. Trump had complied with the subpoena, no charges would have been filed. The reason for charges now is because former Pres. Trump did not comply with a court order and is alleged to have been willfully hiding classified documents.
Now, if it is found that VP Pence is intentionally hiding documents, he would likely be charged. The same with Pres. Biden -- with the caveat that he is being investigated by a Special Prosecutor -- and if the prosecutor finds he broke the law, particularly if he can show that Pres. Biden knowingly kept the documents, he will likely be charged (though it would need to wait, under DoJ procedures, until Biden is no longer the President).
The law is being used consistently, just that the three circumstances, from what we currently know, are not the same. We have no evidence that Biden and Pence knew they had the documents and they were returned as soon as they were found. By contrast, Pres. Trump allegedly knew he had them and was hiding them from the government, which is why he was being charged.
To take it back to Classified documents for a moment, it is still no better for Trump. Yes, while President, Trump could have declassified the documents. Unfortunately, their are tapes (and one specifically) where Trump is allegedly showing people a classified document and admits he could have declassified it but hadn't, and he can't declassify it now since he is no longer President.