You are mistaken as to what you are purchasing and who the intended market is that Dahua caters to...
Most of us here know that the Dahua and Hikvisions of the world do not cater to the "consumer" market - their target audience is professional installers, so we are considered "prosumer" and we are fortunate to get our hands on these types of cameras and NVRs instead of consumer grade junk and not having to go thru professional installers to get quality gear. Now the downside is we get them at a discount and without manuals and support and thus are on our own to figure it out. And we are just fine with that!
We are fortunate a forum like this exists to help with that. We do not exist in their world and that is their business model and they made the business decision to not compete with the Rings and Nests and Reolinks of the world and as such to do offer these cameras at box stores for consumers to purchase directly. Dahua and Hik cater to the professional installers...and would tell you to contact the vendor you got them from if you have questions or need support...
Contrast that with consumer grade units. You can call a Night Owl or Arlo or Reolink or Lorex or
Amcrest or DLink or Google Nest or Ring and speak to a representative (now whether they can help you or not is another story) and for most novice callers they provide good customer service, but they will not tell you to talk to Best Buy where you purchased it...and several of these cost the same or more as Dahua or Hikvision...
Personally I will take better quality cameras and no support and forums like this than crap cameras with customer support that I end up knowing more than the call center person I am calling...
So if you want customer support, then don't buy as you call it "Dahua is just junk" and go run to a big box store and purchase you a set of Arlos and get customer support and an app that works on Apple products...