That’s a good topic to discuss MartinJ.
I have the feeling the answer may be “burn” the miles as soon as we can do it.
I am not lucky to travel enough. Not my choice but real working life currently reduces my globalisation style of work wishes. And this ends with less miles earned. Which means fewer opportunity for free fligths or no more long-haul premium flights.
I believe high frequent travellers may still have incentives to be interested in FFP. But you are correct to say that the constant moving rules needs time consumming to do your homework. I wonder if airlines or other companies are not lost also at a certain stage with their constant moving and sometimes complex rules. I understand it has a cost for them (or maybe they pretend it has). For sure then easyjet is in the right path to say “we don’t want to manage a FFP”.
However sometimes I have the dream one FFP annouces that the mile is worth let say 2 pence. And that can be converted to a MCO deductable when you buy a specific airline ticket. It seems at least we will be able to do what we want even if the value of the mile is inferior to what can be expected when using it with the current rules.
I wish also I could convert that for a Relais & Châteaux voucher, even on a 1 penny for 1 mile parity, and pamper myself in a good restaurant in town.
I notice supermarkets in France stopped to use points in their loyalty programms. They give now monetary value that is deductable the day after when you are at the cash desk. No need to wait ages for the unfeasable airline trip of your life. It is an immediate award. It is of course less fun than a flight but it is immediate and you almost do not lose any value. There is still the question why the price does not include already the discount but I believe this is marketing, no?
And where to leave? Here also it is a lot of homework. I will not earn enought miles in my case anyway. So I don’t spend too much time on it. But I am interested to read what others answer you and to learn from them.
How nice it was 20 years ago when redeeming flights was easy and with no costs at all whatever it is now fees, taxes or surcharges. This time has ended.