It will be impossible for anyone to have a transaction confirmed on the main chain.
This was known since the very first reply to Satoshi's announcement of Bitcoin on the mailing list:
We very, very much need such a system, but the way I understand your proposal, it does not seem to scale to the required size.
To detect and reject a double spending event in a timely manner, one must have most past transactions of the coins in the transaction, which, naively implemented, requires each peer to have most past transactions, or most past transactions that occurred recently. If hundreds of millions of people are doing transactions, that is a lot of bandwidth - each must know all, or a substantial part thereof.
This is why the Lightning Network was developed so you can perform transactions that do not require you to use the main chain every time.