No one has to let you work offline. You can choose to do so yourself by using offline applications if that's something you care about.

But web-based applications have major advantages to the application provider. First and foremost they have better distribution. I can write an app, and then hand you a link (and you know there's no commitment in clicking, so you do). I can show you why you should use my app on my front page, and then I can give you a demo, all without you having to confirm any "are you sure you want to make permanent changes to your system" dialog.

Now of course one can't easily make the above argument for a mouse driver. But I'm responding to your sentiment that too many things are web connected in general.