He has no one to regroup with. The rats have all deserted the sinking ship.
Whether those serving in the cabinet feel they are doing a public interest job, or are just following what they think is in their long term best interest, I do not know.
Ben Wallace, Minister of Defence, who kept a low profile throughout, said that in the current situation in Ukraine and elsewhere. He felt his duty was to his country and ministry. I tend to respond positively to this he is ex-army and I am from an army family and recognise a very traditional military attitude that considers country before politics.
I am not a Conservative, and certainly am not endorsing him for PM, but I do think that most other ministries could manage quite well without a minister for a couple of months.