I can only speak from my own experience of setting up for a 95 year old. Depends what you want them to use it for. If its just to make calls, use one of your older phones (I set up an Honor) and set shortcuts up on the home screen (I use pictures of who he wants to call).
I did set up WhatsApp but only so that he can receive video calls - its all a bit hit and miss though
It depends on how much patience you have to set anything else up. The issue is if they arrive at a page/screen they aren't familiar with
So 82 yo senior, not good with tech and not interested. What smartphone and setup would be easiest?
^^^ yes. You could look at the Moto G8 which is £170 on amazon. It has Android as its operating system and is great if you want a budget option.
I didn't know people still make calls from their mobile phones - JK! Yeah the thing is you also want a good product - there are many cheaper options but then again your experience with them won't be great so I'd say the G8 is one of the best bets if you are looking for under £200 unless you go used or older generationMore like price range, even that if only used for calls is seems excessive.
2nd for the Doro here big buttons, big screenDoro