

I don’t know if Home Assistant is so niche. Everyone who does some form of smart home comes to the point where there are several manufacturers forcing you to use their own app. If you’re lucky you can use something like Google Home or Siri to have a unified control interface, but these are usually very basic. You can try to stick to one system for as long as possible, but sooner or later that will fail. A system like Home Assistant is the inevitable solution to these problems and it is a very good thing that HA exists as a strong and open software to solve this problem.
I also think it may be the browser not using the DNS provided by the router. This is often called Safe Browsing or Secure DNS in browser settings.