So, you may see another post of mine asking about NDAA compliant camera system.
Now, the "IT" guy wants to use the Unifi line of cameras and video doorbell. I've heard decent things about the line and app but never looked into it.
My gut feeling for this project is that Unifi isn't the right choice. The house has 16 cameras currently and will probably need 4-5 more added at some point. It's a high end residence and I feel that we'd be selling the owner short with Unifi cameras.
Please let me know you're input with Unifi cameras and any pros and cons.

i use 3 of the unifi cameras in our warehouse. they were really easy to set up, even outside of the whole unifi ecosystem. (using a simple synology nas drive)  I can't complain about them, but then again, I'm only using 3 of them.

Unifi would be fine to use ,but you will need the UNIFI NVR for recording and either the UDM-PRO router or the GENII cloud key for remote access. Or you could host your own controller.
Before you sell any of this, you should set up at your home or shop and test and research the cameras that would be installed. Also, make sure you have adequate POE power for the cameras.
Other that the unifi community forum, you are on your own.

For what you get they are overpriced and are pretty much locked into the Unifi Protect eco system (yes there are some workarounds with RTSP as Duct Tape mentioned).

There is basically no support and only have a 1year warranty. If staying in the Unifi ecosystem you are stuck with unifi cameras as the recorders aren't ONVIF or RTSP compliant.

I have installed some customer supplied units but will never sell them to a customer (even though we use their switches and routers).

Unifi is also notorious for just ending things and support out of the blue so what is working/available today could be ended at anytime with little notice.

If you buy the product from the Unifi store, the warranty is two years.
I find some products more expensive, but most are not. The new G5 Flex is better than almost any camera at that price point.
More important, you have no fees like ring cameras, but have an app that is better for viewing timeline and setting detections.
a $99 camera with AI smart detections to expensive for you?
They don't play nice with other systems. That is true.
It took a few years to get a good lineup of product. And that is here now.

I did set up a system recently.

The camera selection is limited as is support.

But they were fairly easy fo set up and the app is 10x better than the usual shit from Hikvision and such - like so easy to use I would feel comfortable setting it up for a fairly tech dumb client. Plus you’re having them access the system from a simple website login.