They are not comparable because node-red is a generic low-code programming tool while HA is home automation software.
If you mean how they compare when you plug in node-red to HA and use it for automations, rather than use HA's "native" automations... I believe the consensus is that node-red is more user-friendly in that way, and because it can plug to other things on its own it can provide more flexibility. On the other hand, HA has recently worked on the UI of their automations, and it is already pretty good for simple flows. In the end both of these approaches are great, each with its own pros and cons.
If you mean how they compare when you plug in node-red to HA and use it for automations, rather than use HA's "native" automations... I believe the consensus is that node-red is more user-friendly in that way, and because it can plug to other things on its own it can provide more flexibility. On the other hand, HA has recently worked on the UI of their automations, and it is already pretty good for simple flows. In the end both of these approaches are great, each with its own pros and cons.