As others have said it's all subjective. If you are Avios rich as I was a few years back I used them for RFS all the time. I didn't really care about the value as the flexibility of Avios tickets was better. This was before Nectar which was, at the time and up to the recent devaluation in exchanging, a game changer.

Raffles aka Head for Points does a deep dive on the subject. In summary anything where you get ½p or less in value is poor. They value them at around a penny.

https://www.headforpoints.com/2024/03/25/what-is-an-avios-point-worth-7/

https://www.headforpoints.com/2024/04/17/part-pay-with-avios/