Why are some options only available in the browser extension but not the web vault?

See topic. For example I’ve been searching in settings => options for default match detection within my web vault, because it was claimed within the help pages that I will find the setting here.

Anyway, this option is only available in the browser extension.

Are there more things, which I can only change in the browser extension or maybe only within the desktop app? I always thought that if some place has all options available it will be the web vault. But this seems not to be the case.

What is the reason for that by the way?