If a product is bundled with too many other products to convince you to buy/subscribe (c.f. Amazon Prime), you’re probably overpaying for it!

Airplane miles are similar. They are there to convince you to not take the best deal, but to hope that your loyalty will have some obscure benefit further down the line. The problem is that that benefit forces you to make other compromises on your time, attention, priorities when you try to redeem the miles later on (of course there are edge cases where it actually makes sense to focus on miles, but I think they are limited to edge cases).