I think it has more to do with the cellular modem itself, or precisely the firmware it's running; of which there is much more diversity on the Android side.
When we visit downtown of our city, I get great data coverage. My wife, on a different model but same gen iPhone and same plan, gets nothing. Her phone shows three or four bars but her apps won't load anything.
No idea why, especially since I'm the one who installs ad blockers and such. Her phone is essentially stock.
Android is quiet lazy searching for towers.