All the code to find like terms and phrases and whatnot is great and not privacy threatening, but I wish the search giants would stop trying to guess my motivations and just present me with the most relevant results based on what I asked for, and not what it thinks I was probably asking for.
The point is that the personalization is somewhat useful, and relying on others input to improve search isn't necessarily going to improve things for a particular user.
I'm a fairly prolific. poster and use DDG search heavily. Be the SERP you want to see in the world?
The same as to why drugs or so many other things are tuned towards men (large body of research and easy to grab for tests) vs women (less historical interest, tricky to research, especially anything that can affect the reproductive functions)
If you do not want Apple/Google/Amazon/whatever listening to you, do not use their services/products.