[jakobegger]

This is not true when radios are involved. In my experience, wireless connectivity issues are rarely caused by software; the problem is much more often caused by interference.

The interference can be internal interference in the device, or interference from other wireless devices. In many cases, the problem are even devices that shouldn't emit RF at all, like power supplies, switches, light bulbs...

Another common issue is poor antenna design (eg. attenuation when you hold the device, or strong directionality of an antenna that should not be directional).

And, last but not least, physical obstacles. Most people understand that concrete walls with rebar will block signal, but a surprisingly large number of people try to use aluminum stands or cases for devices with wireless radios.

All those factors will cause connection issues, and they are really common because debugging them is so hard (who has a spectrum analyzer at home? How do you find out which one of dozens of electronic devices is emitting RF that it shouldn't?)