NCB:
Comparing apples and oranges. I have used both. No similarity.
HB allows for download. Then the sefer is on my hard drive. I can print out what I need, and always have access to it. The pdf format is quite user friendly.
Sefaria is a memory heavy website, and won’t open on many devices. Okay on my desktop, not on my phone or tablet (even though permitted by my filter). The text is better for copy and paste into other documents, less convenient in the HB pdf format.
Depends on your needs.