No Stupid Questions

In a non-malicious way it can all be helpful to websites to know the capabilities of your device to allow it to change what the site delivers/how it renders. Knowing your GPU allows it to know if your device supports WebGL/DirectX/Vulkan etc., knowing light or dark mode allows for it to set the site the same as your system, if the tab is not active it can pause content, and if you have a low battery the site can try to be less power hungry by perhaps not asking to render a ton of active content. Knowing if your on a mobile device can allow the site to deliver a mobile optimized layout, or if you have touch capability to render buttons larger.

The fact that advertisers and data brokers use this to fingerprint you as a user is just a non-intended use of good intention features. In reality, if you do hide this information (which you often can using developer tools in many browsers) you’ll find the some sites will just not work or will act wonky and data brokers will still fingerprint you using things like tracking pixels, your IP, or user agent string info that you can’t really hide without fully breaking the web. You only need three or four individual pieces of information to pinpoint specific individuals in most cases so they don’t really need all of it, it’s just easier and more accurate the more information they have.