For me my mobile data bundle (10G) could last me for an entire month with all of my regular networking needs as long as I don't watch YT or Netflix. But since I do I also need a separate home connection.
While it is definitely possible where I live, it will take you at least ten times as long (because it just doesn't work very well and the process is not at all streamlined). Don't even get me started on taxes. Doing those without the internet is the metaphorical equivalent of stabbing your hands repeatedly.
The point is not to be without the Internet, the point is to have more time to spend on things you appreciate; "doing bills" offline takes more time than doing it online.
Rapidly becoming impossible. So many government services now are only available via online. They expect you to go to the library and do that.
That said, if I didn't work from home. I think I probably would outright dump my internet connection to regain freedom. Maybe I would go to the library with my laptop to do the bills. It would create a hard block for needlessly worrying about them.