It's possible to create a circular connection in the UI

[Digital-Larry]

The problem is that what you get is not exactly what you think you should get. You can draw the diagram that way and it will generate code differently depending on "a roll of the dice" - some of which do not work at all. Blocks which want to have explicit feedback paths should be designed that way (where the feedback is internal to the block).

The Feedback loop block is designed to handle feedback loops in a predictable way.