My usage patterns are quite miserly. I rarely go out, perhaps once a week. When I do, if I feel like I need constant connectivity, then I activate Battery Saver

My usage patterns are quite miserly. I rarely go out, perhaps once a week. When I do, if I feel like I need constant connectivity, then I activate Battery Saver and Data Saver first, then Mobile Data. Basically I only use text-based web pages while I'm out and about. No streaming audio or video or downloads. I suppose there's not a lot going on in the background polling, either. Of course I hop back on WiFi wherever possible, my ISP makes that easy. I've been doing this routine for at least a year, and I have warnings set when I'm up around 480MiB. I've never gotten a cap warning, although I've had a few warnings that "Chrome has used more data than usual!"