Expand the quick access, tap on the pen icon, tap on Quick settings instant access, turn on.

You can try “full stop” instead, seems to work better.

Not sure about other countries, but if you’re in the US, you can get an Echo Dot from Amazon, link your phone number, then make and receive calls on it.

By long period of time, what are we talking, a week, a month, 6 months?

If I remember correctly it’s a carrier thing. First Google sends out the Android update to each manufacturer. Then they slap their skin on top of it and do their software tweaking. Then those updates are send to the carrier’s, and they’re the ones sending them OTA to the consumer.

With Apple, everything is “inhouse”.

Usually it’s said, once your phone stops receiving security updates, you should stay away from online banking or handling sensitive data.

If you only use your phone for calls, texts, YouTube etc. you can use it until it breaks.