SIM cards are a relic of an age where multiple people had to share a single phone, and the cards themselves were enormous. These days, SIM cards are tiny and technically unnecessary thanks to the rise of eSIMs.

Many cellular carriers proudly claim to have unlimited data plans, but that's misleading: in many cases, you'll face throttling once you pass a cap. You might have to pay extra to restore the service you expect, and features like hotspot tethering or cellular smartwatches might have their own restrictions.