We all have to make choices, and the OP's analysis shows exactly what can happen with the 'wrong' choice. As is well-documeted on this thread and others, and in the Dashboard, a 2-4-1 in Y just is NOT the way to go.

Without micro-managing the pricing details, I suddered last year when using TWO 2-4-1 vouchers for CW (one to KIN and one to CPT) simply because I couldn't find somewhere in F where the notional benefit would be greater. That said, £420 each in CW to CPT is a lot cheaper than the ~£3k+ each you can see any day.

Using 2-4-1 needs, IMO, long-term planning and a clear strategy of how best to maximise value. Three weeks after our CPT trip, I'm already looking at next Autumn/Winter looking for best value ... and that is CW as a minimum, and indeed about the only way we will use our 1/3m Avios.