I've setup my own instance on a VPS of searx (along with git, blog, private npm and a few other bits and pieces). It isn't particularly hard if you've setup an website on a Linux box before.
I want to host my personal instance. But doing so doesn't make any sense since if I'm alone using it. So I'm better off using Google directly, unless someone can search whatever he wants via a service I'm hosting :/
Well if you use google directly, google can track what you are doing. However if you use your own searx instance that is very difficult. I also host my instance publicly (I've not added to the list because I am using the cheapest VPS from vultr) and for some things I get better results than Google, DuckDuckGo etc.
So as with many things it is swings and roundabouts and is determined on what you want to do. I wouldn't call the model flawed, it just seems that the benefits of it aren't what you want. Which is fine.