jes that is possible, if you use "bitcoin certificates" on a bitcoin holding bank, and transact bitcoin to another user of a "bitcoin holding bank"
the banks never transact the bitcoins, they simply change, the amounts of bitcoins in personal ownership.
"Bitcoin holding bank"? I guess an online wallet, or exchange?
These are offchain, OP is asking about onchain tx's.
Exactly!
My post was not talking about web wallets that do not give you access to your keys and just use a central hot wallet while credting user's account balances in a (relational) database.
Such an online wallet is just 1 single wallet to the outside world, no matter how many accounts exist on their service.
I don't care if an online wallet does not charge a fee to update 2 records in their private database... This is completely beside the point... As a matter of fact, i'd recommand everybody to stop using online wallets