You think you're choosing between 20 different products, but underneath they may all be the same device talking to the same insecure backend. At that point "just research before you buy" isn't really useful advice
Most of them use the same cloud software to connect to the cameras.
There's better solutions if you have a bigger budget, or the ability to roll your own DVR solution...but on the cheap end, you're just stuck with this terrible software, chinese cloud, and...at least for me...zero trust in privacy. (I keep mine offline)
And even when it's in your hands, who has the time and expertise to thoroughly review a product for security issues?