Hypothetically speaking, that will depend on how much interest you would get for having money in the bank.
If the returns you get from day trading is still higher than what you get by leaving money in the bank, then obviously day trading will still exist
Conversely, if you can make more money out of interest then it would curb day trading as people will just save up and make more money on top of their money.
But to be clear. I 100% agree too. This idea is never going to work