First safety. A properly functioning mobile phone from a reputable manufacturer is not likely to interfere with any digital aircraft systems. But that assumes:
* The phone is operating within specs and not damaged
* The aircraft shielding is fully intact and there are no other issues
It's only a matter of time before this causes some sort of issue. Like the Wikipedia article links to, it already probably has caused minor issues. Also, many important systems are analog (like pilot voice comms). I was on a plane that was forced to do a go around at landing because the pilots couldn't hear the control tower due to interference. I wouldn't be surprised one bit if it was someone's phone.
Second, basic decision making in a society. You're trading an extremely low likelihood of putting 200 people in danger or at great inconvenience against.... being able to make a call 6 minutes sooner? Checking your email? To tell someone... what - your plane is arriving? That's all online. Wait 10 minutes.
The number of people with no expertise in electrical engineering and electromagnetic interference who "heard on Reddit/YouTube/from a friend" that it's actually safe to use a phone on a plane and decide to do it is way too high. It's the same thought process as hearing something on Youtube about mRNA causing cancer/magnetism and then ignoring the medical community and skipping a vaccine.
An overwhelming majority of the time, using a cell phone on a plane doesn't matter. But don't do it. Put it in airplane mode. There's not a big conspiracy trying to make you miserable. Experts on this are actually worried about you.