1. This is only my second iPhone.
2. I have apps that have NEVER used cellular data that appear in that menu. For example, Bose Connect is used ONLY inside my home where cellular data (and voice phone calls) simply don't work. I use Bose Connect with QC-35 headphones only while sitting in a recliner watching television in our family room. The headphones have never been outside my house. Many years ago, when siding was put on my house, the contractor also put metal-jacketed insulation under the siding. At the time, the only effect we noticed was that the rabbit ear TV antenna would no longer work. Now, cell phone calls must be WiFi calling and cellular data just doesn't work. Period.
3. I have apps that have NEVER BEEN USED AT ALL that appear in that menu. One notable one is Notes. I tried it on my Mac five years before I bought my first iPhone and didn't like it at all. When I got my iPhone, I was disappointed that I couldn't remove that app.
4. Be that as it may, I'm still curious what would happen if I turned cellular access off for Springboard.