You can't even save user preferences (like language or other settings) without showing a cookie banner. Edit: I was mistaken. You can't save inferred preferences, but can save explicit user-saved options.

And for a serious website, front end analytics are kind of a necessity to understand how users interact with pages and improve the experience. Note that it certainly doesn't require tracking the behaviour of individual users, just understanding how controls are used in aggregate.

I know it seems like you could work around this with careful design and maybe focus groups and such, but I can tell you we regularly uncover surprising insights from (aggregate) trends in front-end events.