Fingerprinting is about more than just the browser you use or cookies you allow. It is also stuff like the pixel dimensions of your browser window. That info is available to websites so they can display their website correctly. If you have a more rare computer monitor in terms of pixel ratio or pixel count that automatically narrows down your fingerprint. The browser add-ons you are using are also easy to know, so the more browser add-ons or extensions you are using the more uniquely identifiable your computer becomes. In many ways, using more obscure browsers, more specialized add-ons for security, etc. actually makes your computer more unique because there just aren't many people using those things.

You need to think more like you would if you wanted to be anonymous out in public. To become as invisible as possible, drive one of the most common vehicles made, in one of the most common colors sold, have zero unique identifying parts added to the outside, and drive with the flow of traffic everywhere you go. If you instead drive a rare car in a strange color with bumper stickers all over it you will be obvious wherever you go.