A lot of Biden's behavior is due to his very obvious dementia. However, I believe that at least some of it is intentional or subconsciously intentional.
Biden HATES being President. He hates responsibility and he hates work, as he has all of his life. Biden would much rather be vacationing for the rest of his life, and to be freed from the White House 'prison' in which his is currently confined and controlled. He wants out! And all of the obvious gaff after gaff are, in my opinion, A CRY FOR HELP. Just like a prisoner of war, Biden is telegraphing publicly that he wants to go home.
Biden is not a 'leader' by any definition, and he does not want to lead anything. He is much more comfortable in the background where can hide in the shadows and no one expects anything from him and he is never held 'responsible' for anything.
If one, settling a pillow or throwing off a shawl,
And turning toward the window, should say:
“That is not it at all,
That is not what I meant, at all.”
No! I am not Prince Hamlet, nor was meant to be;
Am an attendant lord, one that will do
To swell a progress, start a scene or two,
Advise the prince; no doubt, an easy tool,
Deferential, glad to be of use,
Politic, cautious, and meticulous;
Full of high sentence, but a bit obtuse;
At times, indeed, almost ridiculous—
Almost, at times, the Fool.
I grow old ... I grow old ...
I shall wear the bottoms of my trousers rolled.
