The most annoying thing about iPhone Maps for me is the inaccuracy of the direction indicator. I've googled and it doesn't seem to be a universal complaint even though I've experienced this on multiple devices over the years even after following instructions to re-calibrate multiple times. Maybe I've just been unlucky.

It intensely frustrating to use maps for direction finding while walking or cycling when the app is telling you are facing one direction when in fact you are facing another.

Settings - privacy - location services - system services - compass calibration. Make sure it’s enabled. In a bout of paranoia I disabled location for everything I didn’t recognize as necessary and then it took me many months to find out why compass cone behaves funny in mapping apps.

On my past iPhones, the compass always got screwed up over time somehow. Sometimes recalibrating fixed it, but only for a minute.

That's a phone compass problem no? Perhaps the specific way you're holding the phone is confusing for the algorithm?