Blockless blockchain is possible, but locks are necessary to reduce transaction size. If that was not there, each transaction will take all the data with it and it will be bloated soon.
Bloat can be dealt with since disk space and communication speed follow an exponential progress similar to Moore's law. But what about transaction speeds? Paying for a coffee at Starbucks should only take a few seconds at most. 0-confirmation transactions or payment channels can solve that problem for coins with a block chain. It would be better though if the real transactions would be fast.
We are talking of orders higher bloat, and that will increase with more transactions. In effect we are talking of a system where each transaction is a block. Its nearly instantaneous as the block is created whenever it transacts, but the size will be huge.