The majority of people in the UK only have one bank account like me so I am actually full Starling.
The full Monzo thing is laughable because they usually have ten bank accounts and don’t even use Monzo for anything. Monzo probably makes a loss on these people while they boast about being full Monzo 
No idea about full Starling because that was never a trend but there are definitely more people who will use Starling as their sole account.