My cynical answer is: unless you have a minimum feature set users want you don't have a product. Whether it has authentication or not is kind of secondary to this.
More constructively perhaps, if detailed authentication is a critical feature then adding it now might make sense. But if simpler authentication is acceptable, you may be fine adding it on later.
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My cynical answer is: unless you have a minimum feature set users want you don't have a product. Whether it has authentication or not is kind of secondary to this.
This unfortunately leads to a horrible quality cycle, one I cover in are we forever cursed with buggy software
More constructively perhaps, if detailed authentication is a critical feature then adding it now might make sense. But if simpler authentication is acceptable, you may be fine adding it on later.