I have a video doorbell for three reasons:
1. Because I want to know when a delivery occurs so I can promptly retrieve the package.
Most of the time delivery staff don't ring/knock or I may not hear in my office, a simple motion detection camera would do this just as well, but a combined device is simply more convenient.
2. To record who enters and leaves my house and when.
Whether it's friends visiting or a home invader, it's important that I have a record of this in case I find myself in a situation where I need this evidence in the future. For better or for worse (and I think for the worse), the mere existence of these devices means lacking this evidence can be incriminating against yourself, so having evidence to support your own case in the future is simply prudent.
3. So I can respond to people without needing to open the door.
There are all sorts of solicitors and others who go around ringing doorbells, and in general I don't want to speak to them at all, but I also find it more expedient to respond. By doing so through the doorbell I don't have to open the door and expose myself to forced entry risk (which unfortunately is commonplace).
The funny thing about insurance is, that there's no insurance that reasonably covers your packages once a confirmed delivery has been made but prior to you retrieving it, and there is also no insurance that covers the results of a home invasion or incorrect (possibly malicious) prosecution, other than possibly replacing non-unique property (after deductible). An ounce of prevention is worth a pound of cure.