The problem with low-code is the same as with outsourcing code on UpWork:

Security

You get something that works. But how do you know there is no way to:

1: Alter the code from the outside

2: Access parts of the DB one is not supposed to access

Those can only be avoided by a programmer who knows about all the weird edge cases that might lead to 1 or 2 and how to write a complex system in a way that is structured to make bugs unlikely.