Re: The easy solution
…and, with regard to the battery problem, Apple replaced the battery and serviced my iPhone 7 (service probably didn't amount to much more than giving it a quick buff with a micro-fibre cloth) for £50.
£50, and it feels like new again. It's got its endurance back, and it isn't throttling any more. It's got the latest OS on it and, honestly, I don't think that there's any phone from any manufacturer running any OS that does anything that my iPhone 7 doesn't and that I'd want it to do. Which makes £50 a bargain.