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.