The QAnon crowd noticed the continuities between the Trump and Biden administrations and came up with its own explanation. Biden, they say, has long been killed by the generals who remained loyal to Trump (in another version, Biden was arrested and sent to Gitmo). Trump is the true president and is carrying out all the presidential duties in secret. The secrecy is needed to draw out the swamp members who would sabotage Trump
I didn’t find this online but heard it from real, live people.